Should I move on or give one more chance ?

My Boyfriend and I have been together for 3 yrs and 8 months , We mostly bickered at each other more than anything . I know he loves me ,and he writes me letters to let me know how he feels. he can't really sit down ,and talk he holds it all in. We took a break for a week we started talking ,but we never sat down ,and talked out our problems. So he started talking to this girl has friends ,and he said into more . Now he is wanting back with me ,and I just want to know if I could trust him. He told me their never be another girl like me ,and he regret what he did he had the perfect life ,and he screwed it up . Do you think he will change ???