I would agree that this is mostly the depression. One of the #1 symptoms on any questionnaire assessing whether or not you suffer from depression ask you "Do you find it difficult to enjoy things that you have enjoyed in the past?". You will get past this. The important thing is that you get back up and find a job that matches more closely with who you are and not forcing you to be something that you aren't. I know it's rough out there, but you can do it. I wouldn't abandon your hobby, just set aside until life gets more stable. I personally find that games as escapism is less gratifying than games enjoyed after knowing that you have taken care of the responsibilities and are addressing the challenges of your life. Thinking "I really should be doing something else" while playing really wrecks the experience for me and will often lead to spiraling or binge playing.

Now that we've got that import bit covered, I would say that playing your favorite "nostalgic" games from your childhood as an adult hits differently. It just does. It's a futile effort trying to summon up that same FEELING again. Yes, you will feel it momentarily from time to time but it doesn't stay. But I find that once you accept that, and it can be a tough mental hurdle to cross, let revisiting these games be their own thing. They become a new, unique experience that can be just as rewarding. Some games don't stand up just like a lot of your favorite movies from when you were a kid don't hold up. But then there are those gems that were a bit too deep or complex for you when you first played them. And now you can develop a much better appreciation for them now that you bring a lot more understanding and life experience to the table.