Is it normal to feel like a bad person... after..??

A couple of months ago, my best friend stole the LovE of my life. Like he was my everything. I was mad and threatened to end our friendship. I was pissed and said tons of hurtful things but eventually he came back to me and we made up; but I still don't trust her at all and question my forgiving her.
Then in August she let me meet her latest boyfriend. We were arguing alot. Over that and my ex (her step brother) who used to abuse me and it was the first time I had see him since so I was off.
She ran off with another friend of hers, because I upset her. So it was me, her boyfriend and my ex . Of course I was extremely uncomfortable. Do her boyfriend and I went on a walk while she cooled off. We hit it off right away.
And starting texting and sexting all the time. Then one day we met up. And did more physical things.
Technically I am still a virgin. It never went in me but touched that area.
My ex was my first boyfriend ever. The first guy I kissed.
I don't know if that is normal, I mean of course not stealing her boyfriend but my hormone Spike?
Is it normal to feel like a horrible person after this and that I don't deserve anything. Or anyone?