The end of the line

I have a problem with my man. He wont let me be myself in the relationship. he is 20 years older than my 30 years, and maybe thats why. But we just seem to argue all the time and get on each others nerves, and be moody with each other alot. He said on saturday that he felt we were reaching the end of the line, as he cant take any more arguing. He is divorced and has been for 12 yyears. He wont live with me or marry me. That upsets me. However, we do have fun together and do fun things together. We really love each other. help. I feel its only a matter of time before we will finish at this rate and i dont want that to happen. how can i stop it and help our relationship? H