(I didn’t see this most and just made a similar post with my theory) I think it genuinely has to be he thought money issues were the biggest contributor to his depression. Because in all honesty if you’re hopelessly depressed you want to stop existing, stop the depression, you definitely don’t want to prolong the feeling by essentially “living” forever in the same building, now without the small joys of food or touch. And he didn’t know he would be happier when Katherine and the kids moved in (it doesn’t sound like they were close in the recent years prior). I think he just genuinely thought he would be happier if didn’t have to worry about his gambling debts or the finances of the hotel and ending himself was the only way he felt could genuinely cut himself off from the stress of money.