i fucked up

another break up story... not going into details... but the moral of the story is that my jealousy and insecurity got the best of me and ended "what i thought" was a really good relationship... i just wanna know whats the best ways to deal with all this... like... i wanna keep calling him and telling him im sorry and i love him to pieces... but i wont... im not that bad... but he is so determined to not get back together that it makes me think there is someone else... like maybe they are giving him an ultimatum or something... we are 2 hours away from eachother and have done the best we could as far as having a normal relationship goes... i just fucked up and i wish i could go back... any break up remedies?