I think Trump might be willing to run again, but he's going to spend the next few years dealing with the immense legal consequences of his actions, and I can only assume his health is going to permanently decline. (I mean, the guy's in his mid-70s, has a horrible diet and is in horrible shape; surely he's only going to get worse from here.)
I don't think he'll ever commit suicide, however. His pride wouldn't allow it. He'll linger on for as long as he can.