<human>: Give me the gist of the text in a nutshell

I've been with my boyfriend for 5 months now. And I feel different from when we started seeing each other.

In the beginning I was happy, there were some things that bothered me, like he didn't talk much, got irritated easily and was short on text, but I didn't care because I was the opposite and I liked him. 

Now I get angry at him all the time, for minor things that didn't bother me before, and even if he's happy and tries to cheer me up I just can't let it go. And he's changed too, for the better, he's much sweeter and makes me feel loved. 

I'm really insecure so even though he makes me feel loved it's not enough, and I used to be all over him and sweet but now I don't want to and I don't know why. I have also become more immature since I met him, before I used to talk about problems in a calm way, now I just blow everything out of proportion and I don't know if it's my insecurity that's acting up because it feels like if I'm thinking "I'm not sure he wants me so if I'm a pain in the ass he'll dump me and I will be right"

And yesterday we got in an argument and I bit him... understandably he told me that he didn't want me anymore and to go home, but I told him I regretted it and after a while he said he still wanted me. But today everything is eating me up inside, I feel guilty and kind of scared of myself, in a previous relationship I was really manipulative and abusive and I thought I've learned from that and now this happens. I don't want to be that person. 

I don't really know what advise I want, it feels good to vent, but I want to know what an outside perspective says.
<bot>: I pick dumb fights with my boyfriend and I feel like I've changed since I met him, don't know what I should do.