How do i express my feelings in a letter?

I met a guy in the begging of the year his name is aj, thing were going good we dated for a while but he still had some feeling for his ex and did not want to start a relationship with me until he was sure about us, some things happen we stop talking few months later he comes back looking for me and wants a chance i gave him the opportunity.. then went out to eat and i saw a picture of his ex and him hugging and i was upset i told him to let me go.. few months later i started talking to another guy and had a relationship then aj comes back to improve to me he wants me back to forgive him, i wasnt sure but everyday aj will improve to me and show me how he felt he gave a rose everyday wrote me love letters and he knew i was in a relationship he told me he would wait for me and at that time i felled in with aj now that i broke up with me ex aj is not sure about me.. i tried calling him and told him wat i feel, now i just want to write a letter how i feel that i miss him and cant stop thinking about him and i think about the moments we spend together and how i can still feel his touch and body and the beautiful memories and sweet love we made. Can you help express that in a letter please?