I first told myself, “just move along and keep your mouth shut”, but I can’t help myself so I’ll apologize up front if this sounds a bit cruel.
My own humble opinion is, you should beat yourself up everytime you lose a living creature you are caring for. We have control over their entire existence. If you don’t feel crushed when a creature in your care dies, then you don’t really care about them as much as you should. Beating yourself up shows you care and motivates you to try harder to keep them not only alive, but happy and beautiful. That’s the reward of a good caretaker.
Have I lost coral and fish? Absolutely! Have I given up? Never! I double down, figure out what’s wrong and make it right. Some couldn’t be saved, but many others could be. I would almost venture to guess that my biggest feeling of achievement is almost losing one and being able to bring it back to a healthy happy coral or fish. That is why I’m in this hobby.
I would say, don’t beat yourself up for beating yourself up. Just feel like crap, get over it and try harder. At some point, you will find the grove and you and your critters will both rejoice. And, if money is the biggest driver, then grow tomatoes. This hobby is expensive. But, the rewards of a happy healthy tank are worth it.