Hello ladies. I'm a long time lurker and sometimes a poster from my another account looking for help. I feel like I've dug myself into a hole and want advice/reassurance. Excuse me for the wall of text!

Background

I and him are both in our late 20s. We've known each other since our teens and reconnected 3 years ago when I was in a really bad place mentally. He helped me rebuild my life, poured god knows how much money into me, and nudged me to get therapy. Somewhere along the lines, we became friends with benefits. I think this is important to add: he didn't orbit me before this happened and he never seemed desperate for female attention as he had plenty. We discussed our boundaries and he was firm that he wanted some single time since he had just gotten out of a long relationship. He made a point to tell me that he liked me and at some point definitely had a crush. Another important point: I always felt that my mental state was a deal breaker for him (the absolutely right thing to do). He saw a lot of outbursts and unstable attempts to communicate how bad I thought life was.

I was getting a bit better though, we spent a lot of time together (he initiated a lot of it) at his place talking about everything, cooking, watching movies, and having sex (sex was great). We traveled together and did everything together and it felt just right. He confided in me and told me everything. He always mentioned me in his plans for the future (travel, possibly moving to another country, trips with his family) and maintained that I was the closest and dearest person to him.

What is the problem, and what do you think is the root of the issue?

My neediness, clinginess, and lack of self-esteem. Somewhere along the road I got used to him being my main source of support and kinda got lost in it. I didn't do my hobbies, I didn't put in an effort to maintain a connection with my female friends (or any friends) and as a result, I would get extremely insecure when he did anything without me like meeting with his friends (we have a group of friends that we both hang out with, and he has a group of guys he was friends with long before me). I would nag and make a fight out of anything, from doing stuff without me to instances where we'd have no time to have sex and I would feel unwanted to nitpicking small things. We'd fight, I'd apologize, then it would happen again. Three months ago he told me that he wanted to take time off. He said he realized he felt suffocated and pressured and he needed a step back, he still liked me and was attracted to me but wanted some space for himself and to be just friends while he's recharging. He maintained that he wasn't seeing anyone else (I trust this) and it didn't mean that he decided to never ever be more than friends. He did get very defensive when I tried to talk and pry (bad idea), telling me that while he liked me, my behavior was extremely offputting. He stopped engaging with me when I would ask him over and over again if he liked me. However, he encouraged me to get therapy, pick up some hobbies and work on loving myself. When I asked if he'd rather cut contact, he said he doesn't want to and that he likes spending time with me.

Another thing that puts me into full-blown panic mode is the fact that he has a new female friend who he talks to every day. She is a part of an online friend group from across the country that he got when he decided to take some time for himself. When I asked about her, he told me that I should not be paranoid about it, that he did like her but they were just friends with no plans to meet and nothing that would lead to something more and pointed out that she's in a different city far away. I have no reason not to believe his words since he never lied and never tried to hide things from me. However, I think he feels my insecurities around this and feels pressured to reassure me that everything's fine. They added each other on all socials, however, this is not out of character for him to grow close to a friend. From her pics, she seems like someone who is not her type, based on what he told me about his preferences - she's way heavier. I also kind of think it's not very rational to think that this will lead to something super serious based on all the factors? Still, I feel paranoid and defeated and like I have zero chances to ever mend things with him because of the girl.

How have you contributed/attempted to mitigate the problem?

I'm back in therapy. I have a great understanding therapist who I feel is pretty RP. She doesn't have any of the "you go girl, leave him immediately for any reason you're always right" attitudes but is very comforting and realistic. I'm working on my insecurities by myself too, using simple CBT stuff like trying to find and confront irrational thoughts. I'm reconnecting with my female friend group. I'm working on my fitness - I have a healthy BMI but some excess fat that I've started losing. I stopped emotional overeating. I started journaling as an outlet for negative thoughts that I previously unleashed on the guy I'm writing about. When he plans time together, I make sure I'm acting pleasant and we're having fun. I'm keeping my mouth shut if I see a chat with the girl open on his PC (we work together). I'm mindful of how I'm talking to him, eg. not insecurely asking whether he really wants to go to that movie together, as if I doubt his ability to decide what he wants. I realize it's going to be a long hard road though. Ideally, I'd want him to be around when I do get better. I feel like we do have a strong connection and would like to see if this leads anywhere when I'm more self-reliant and he doesn't need to act as my therapist and caretaker.

What is your current relationship status and length of time?

We're still close, but not sleeping together. All of the plans for traveling (just the two of us) and getaways with friends are still valid. He tests me through the day, asks if my therapy appointments went fine, and says good night to me. He still suggests time together and still acts playful around me. I am in panic mode though. How do I get rid of this feeling of being defeated by an online girl from another city? There's definitely some victim mentality here, why even try if she's won already. Why the hell would he do so much for me for all these years? Am I being irrational in thinking that I have no chance because of her? I know I'm the reason I'm in this mess, not some other person but still. Do people ever get through this? Any advice will help, thanks in advance, I know this post probably sounds really stupid but still.