Need Advice!

So, I have a hard time trusting my husband. And it doesn't help that he goes behind my back to talk to these girls. talking negatively about me and our marriage. then he comes home and act like everything is ok. I will catch texts between them and talk/yell at him. then he will change his password. And I will catch him doing it again. this time, he was talking to an ex that I cannot stand, and mind you, he has unblocked and reblocked her multiple times due to me finding out that they keep talking behind my back. I love him, and he doesn't give me any other reason not to trust him other than that. But I honestly don't know what to do about it anymore or how much longer I can keep dealing with it.