This is going to be divided in 4 acts: motivations, before the break up, the break up and the after break up.

TD;DR: Things are not going as expected, I'm not ready for a relationship (don't want it at all) and my gf wants marriage, kids, buying house... The whole package. So I decided I should start working on the break up of this relationship. We've been together for 3 years and it's been 2 years we are living together. And this is the tricky part, we are living together.

You don't need to read my motivations to help me

Motivation (very very very selfish, but this is me):

I had time to experience what is a life with this girl, and it was very positive. But I realized it is not what I want, I want to be on the wilderness for longer, move to work my ass off, it's time to take care of myself, I'm not really happy supporting my gf,her family,all those problems, attention,discussions, family parties (egrww). I'm not a family man, I just can't take a shit about anyone but me. I want to live this moment untill the day I'm ready to be part of a family. I want to travel and live in a lot of places (my career allows me to do it) and for now i can't stand justifying myself for some bullshit i want to do.

So lets begin:

Before the act

So what should I do once I'm certain I want to break up?

Should I look for an apartment to be sure I won't find myself homeless? Or it is too soon before the act? I'm afraid this is not going to end well because she is rather reactive. So lets get to this. How do I should deal with her family? Those guys are very protective, I'm not sure they will take it well either, 70% of the family is female. Bills and stuff how do people break up over these this things? We've always shared everything. I'm not sure how she's going to react.

Context: I'm alone in this city/state/country/continent, I don't have a family or good friend in less than 12h+ flight.

The act

I need a good strategy because I respect her, what is the best way to do this? Disappear? Letter? Leave message on the voicemail?

I open myself, she realises we should break up and helps me move. Hell no, she doesn't have any good reason to break up with me. This is going to be a long day/week/month. I don't want to fuck it up more than a break up of an almost marriage is so... Should I prepare myself (I'm not sure what) and go easy, let her lead the boat? How frustrating and long this is going to be, it's going to take weeks if I let it go naturally. What is a good setup for this situation? Sleep on the couch? Sleep in the same bed and end up making love with your ex that lives with you?What a nightmare. Should we agree over something? Shes going to try to convince me to stay with her for longer (this is not going to happen). How do I react? She'll never accept it and let me go like this.

Note for myself: hide alcohol

The after act

Ok, if I'm not homeless i go to new apartment and send her a message "yo forgot my favourite t-shirt" and she'll give it to me next time she stops by? Hell no, what happens in a after break up like this? How do I prevent a comeback/rebound?