Break up

(maybe the Title is rambling!)  Patrick has recently broke up with me, again.  He also has a head injury, but he sustained it as a teenager.  I have to have compassion for him because he does not know how to think as a 40 year old adult, heck there are alot of things in life he doesnt know because of his head injury and he has been so coddeled all his life by everyone.  I know that alot of what he says and does is not his fault, but it sure hurts.  I am want to be his friend but I am having alot of trouble going backward (thats what I call it) in our relationship, especially when he doesnt know or understand the differance.  I dont know, all I do know is that I hurt and I do know from past experience is that this hurt just doesnt go away quickly (but it has been over 3 weeks!).  I know there are alot of things that I have to work with him about, but why should I?  If I care like that, it hurts and gets very frustrating because he takes it as a sign as love and forgiveness.  He doesnt feel he can be a grandfather, I have three adorable grandchildren, he hasnt even been a father yet.  (jeeze my son didnt ask me permission to give me a grandchild!) Then he calls me the next day and he has met an old girlfriend and she is willing to give him the children he wants so we are over, then a few hours later he is calling me again trying to get back together because it didnt work out with this old girlfriend.  sometimes he makes me so angry i could spit, but it is not his fault right?  He got his head injury 30 years ago, the same things were not known about the recovery as 12 years ago and maybe he is not able to learn now.  I dont know, all I do know is I hurt! at least I am past the feeling horrible stage!!