what can i do

what can I do my so/baby's father has been acting strange and wanting to throw out his phone and all kinds of things because lately I've caught him doing some things I think are cheating like having a meet me account back up and snapchat we agreed we got rid of everything cause if previous problems and once again he gets them and deletes them before he gets home I know all this cause I seen them in his play store as it shows everything and yesterday he had Snapchat but lied and said it was for us which I don't believe and this morning I tried grabbing his phone and he got mad and he gets mad when I try to look at it which automatically to me indicated he's doing something wrong and I refuse to stick around and look stupid and be played but everytime I try to leave he always says something about my family and that he will take my child that were having together simply because he doesn't like my family which is completely stupid of him because my family is actually really great and they would help me more