I need help..

Okay, so me an my boyfriend have been together almost 9 months. He started acting weird and was jumpy with his phone. I've always felt like I wasnt good enough for him and ive had bad relationships in the past. He fell asleep one night and I couldnt sleep because I was worried. I went through his phone. He was texting this girl, calling her baby an saying he wanted to take her clothes off and stuff like that. We argued over it and I gave him another chance because I always give second chances. Everything was good for the first couple of weeks. Like when we first got together, but now hes started to act the way he was before I found out. I really love him and I dont know what to do about it.. Please Help..