I love him very much, and need advice and help.

Theres this guy ive been dating for 4 and a half years. At fisrt he was so nice to me, always sending loving text messages and a bit clingy and I loved that about him. I understand people change but he has changed drastically and I really don't want things to end between us. I love him so very much. Heres the problem: as of late ive been finding it hard to trust him, we've been using this app to tell each other where we are but he turned it off and I no loe have been having very bad anxiety and depression. We get along in person but when we are away from each other we always dissagree and when I want to talk to fix the problem(s) he gets even more upset and threatens to never talk to me again...and when i ask to talk to each other in person I never really say what's on my mind. U really want to learn how to trust him again, and I really want us to be close at least abit similar to how we use to be. I want us to listen to each other, communicate, amd comprimise but it seems like its not something he wants to do most times. I need help, any ideas as to what I could say or do?