My boyfriend cheated on me. i forgive him. he wants me to stay and help him. stuck, lost, and confused? ):?

he cheated and lied for numerous months. he cheated on me with an ex gf of his over skype, fb, texting/sexting etc. i love him to death and have never had a connection before like what i have now. we were so involved, our familes, friends, everything. and i found out he was a damn good liar. now he says he has changed his ways and admits to all the wrong he has done to me. he wants to spend the rest of his life with me. i wanted to forgive him, and it was a struggle..but i managed. half of me wants to stay with him and work things out because i love him so much to give him chance after chance. he wants me to be the girl to help him change all his wrong ways and i want to be that girl. but the other half of me is so hurt and has so much self respect that i feel as if i dont deserve this anymore. he doesnt deserve another chance. he lied and cheated and i can do better. im so lost and confused. i'm stuck. and it hurts and is a struggle for me every single day. what to do?