I need mens opinion

I have been in a relationship for a few months now and I'm dating this really good guy. He has started to close off emotionally and have lots of mood swings. I needed to know what happened. Anyways, during a conversation he told me that he's taking hormones (by doctors suggestions) for his hair. I feel like this is what is causing the mood swings.

Sometimes he's really nice sometimes he gets irritated so easily, I can barely talk to him. He is also not a social media person and doesn't spend much time on it.

He has also been so stressed out from work (he is being asked to do overtime almost every day).

I don't know what to do, we are long distance for this month but I will see him in April.

In the meantime, how can I be of help? Or what do I do?

Edit: he once brought up ending the relationship and we decided to talk another day about that, the next day he apologized for bringing that up.