My bf

Me and my bf have been together now for almost 7 months but he's living with his mom so we haven't seen eacother since we've started dating . So we rely on our phones to communicate. He dosent trust me at all and I don't know why Everytime I go out he assumes im with guys and goes off and says hurtful things like we're done and go talk to dudes when really im with my friends just hanging out. Im doing everything I can to make him trust me but he won't . How can I make him trust me ? Or can I ? I just want us to last