He seems to be under a lot of stress as it is.
He sounds like he could benefit from some therapy sessions to help him deal with what he's going through. Thereafter it would be possible to give a more accurate dx. A therapist or psychiatrist would be involved in this process.
Personally, I don't think the way he's acting and behaving does not limit him to a dx of Bipolar. There's so much going on in his life right now, that everything is inter-related.
He needs to sort the stress out first. And it may entail you having to take a step back, however hard that may be right now