(How old are you guys?)
I dont know your whole relationship.
But i would say communication is key.
Just sit down with him and talk about whats bothering you. Have a conversation about what the both of you consider as cheating and what not.
Tbh i dont think liking pictures of girls is considered cheating, however i would not like it if the girls were naked or in lingerie. I completely understand that you dont like the post he liked. And find it ridiclous that he gets maf at you about it.
You have to ask yourself if you will ever be able to trust him. If not, its better to let him go. Because in the long run you would only get more suspicious and be the crazy one. And tbh a relationship where you have to be suspicious all the time isnt worth it and doesnt sound fun to me...
Please keep us updated and good luck sweetie.