My longtime bf doesn't touch me anymore?

So we have been together for a while. The past few months we haven't had sex. He's saying its stress and what not but he used to say this before and it never affected him. He says he can't even get it up but i think he is lying to me. I few weeks ago he got hard and lied about it saying it was a morning wood or whatever. I found clothing this white stuff on it and he swore he didn't know what that was from. Well he still hasn't touched me. Then today i just found more clothing with small patches of white spots in an area like if he was hard and then put it away later and left more lower. He swears I'm attractive and it's not me but it's really really getting to me and my insecurity. Like why doesn't he want me could there be someone else? I don't even know how to bring this up anymore because he makes me feel like im crazy. He says it's nothing and just gets angry. But if he's still obviously getting hard and touching himself then why doesn't he want me i just don't get it. ( which a couple months ago early on into this no sex streak i caught him touching himself)

Something isn't right. The white stains are evidence that he does climax. He either masturbates allot or he's banging someone else.