It will really come back to normal?

It’s been 12 days since I started this journey, I’m feeling good about it, and I feel proud of myself for trying to change. But, sometimes I wonder, i lost my virginity at a really young age (14y) and started with porn a little bit of time before that. I have a girlfriend right now, and sometimes sex doesn’t work that well for me, I feel like I’m not that amused by the situation, and sometimes I don’t get that hard when we begin. I stopped with porn and I had some ups and downs on that matter, some days with crazy libido, and in other ones, with the problem of being “not that hard”, I still think about scenes, about other expectations, and I just can’t make myself that hard sometimes. It even makes me take a long time to get there, but it doesn’t matter because it doesn’t feel good. Can this new habit break that cycle? Can I go back to feeling really excited about the sex with my girl? I already saw some change with the crazy libido days (those are new for me on our relationship) but I fear that I’m too far behind to ever go back to the “normal” that I was before, and that scares the shit out of me.