if he were more logical and less focused on his feelings, he would be more like an intj and probably have an easier go of it. he would accept the situation from a Te perspective and do a better job focusing on what he can control. but he's not, like other infjs, logic is less naturally under his conscious control, so help him get better at using Fe and continuing to improve his Fe management so he can get out there, stop fixating on specific negative judgments, open up, and get better information for Ni to use.
if he can clean up Fe a little bit, he'll sure as shit have a MUCH easier time using Ti productively. rather than destructively, justifying his worst fears and frustrations with false pseudo logic.
also, your last paragraph is irrelevant. perhaps you are upset that he is skating by easier than you did according to your standards of justice. but fuck that- he's struggling and helping him would be a better thing to do than criticizing him in a way that maybe satisfies your own desires but doesn't help him at all. unless you think tough love is the only answer to emotional frustration and struggle????? not to mention, it's not like you're in a situation where he's personally a drain on you, all take and no give. we're offering nothing but a few words of encouragement that are totally voluntary.