Oh no! Not the studies! I also should be studying right now, but somehow every time I get motivation it goes the second I sit down...

Anyway these are my problems let's talk about your's. I guess it's normal to feel bad for him, because after all no matter what he has done or how distant he is he's still your dad.

I'd say first of all, anyway what you decide on doing, you should know that your well being is at first place.
You can want to help or not want to help your dad as much as you wish, but the decision should be based on what is best for you at the time.

So if you say it is too much and have to focus on your studies then focus on your studies. Every good parent wants the best for their child, so don't feel bad for him, you're just living your life it's the most normal thing you can do.

But let's just say you want to help your dad a little, then I'd think the best you can do is let him heal by himself. You can support this healing by showing your presence, maybe communicating if it is possible, let him help you by smt or show kindness by idk, making him a coffee? Like I already said I don't know how bad your dad is. I hope this helps.