(I tried posting this on r/NoFap but it looks like mods don't like this or whatever, so I'm going to post here because this community actually gives rational advices and is friendly to answer)

I'm 19 yo and doing nofap for almost two months now but am having sex regularly (1-2 times a week) with my gf. I stopped fapping and watching porn, because I realised I had been doing it almost only from boredom. And also I was watching types of porn that make me feel ashamed and even question my sexuality.

Nofap made me realise that all these wierd porns and fetishes are only result of my brain getting used to classic porn and needing new stimulus. Also NoFap helped me heal my death grip. Before I always needed to cum from handjob, but after about 2 weeks of not masturbating, I was able to cum from Bj alone and it started to feel so much better than Bj-s before.

But, what concerns me is the fact that lately my erections while I'm having sex with my gf started to feel a little bit weaker. Penis just doesn't feel as hard and big as it used to be. Gf also noticed this. I want to know what could possibly be reason for this, did any of you have similar experiences with NoFap and what should I do to fix it.