I hope you listen to all the great advice here. It may be harder than you anticipate to extract yourself from the relationship, either because you have feelings for the man, or because he will say he can "change."
The thing to ask yourself is: would YOU do something like he has done, with the texting and calls to exes and other female "friends" while building a loving relationship? Of course you wouldn't and you haven't and you never would. A man (or woman) who does this sort of thing is not considerate, in fact, downright rude and dishonest. I hope you can end this relationship without a lot of hassle!