I don't know how to stop

I really don't know how to start... I'am 20 and I began watching porn at 13. At first it was without masturbating, and very few times but then when I turn 18 I began doing it again and everytime more and more often.
I think it changed because at that time I was in a toxic relationship and she inspired me to start masturbating, but I didn't feel as excited as I was when I watch porn. All our sexual activity was basically in public spaces, were quick, and the first few times I wasn't totally in the mood or the disposition to do it, but I never said it. I was very ashamed, all the time, with our relationship, with the masturbation and the porn but I continued.

We broke up, but I was still ashamed of my sexuallity, untill today I don't feel totally cool with it, even though I externally look like it, I think. This confusion I felt and untill today feel, makes me very nervous about the idea of falling in love again, and to satisfied I watch porn and masturbate because I thought it was easier. So anyone gets involved in my confusion.

The problem is, I have had get involved other people, I have give them false hopes and I think, basically because I don't feel sexually atracted to them, and I don't is that is just me or them. Anyway I don't feel comfortable being slave of watching porn, or thinking about, or masturbating really. I don't know what to do.

This is the first time I talk about it like this.