I can sort of relate to this feeling...except I find there are a few things I do enjoy and have sometimes found myself enjoying moments of life but that is short lived. I've had depression for years as well as anxiety and PTSD which was from something that happened after I already had been suffering depression and anxiety.

Don't have a relationship or job, some friends close family but I'm still miserable which makes me feel bad because it would be easier if no one cared and so I wouldn't have to worry about upsetting them by being so down on myself or attempting/succeeding at suicide. I find drugs are the only thing that has really provided significant relief(even if temporary) and drug induced euphoria is probably the closest thing I've felt to actual joy or happiness as sad as that might be. Not sure where I am going with this...I sure don't have a solution or way to fix this sort of feeling, but I do understand some of what you feel.

But yeah I think sometimes people think people with more money or whatever who are doing well enough financially...must also be happier or assume (why should they be depressed) but when you suffer with depression or other mental problems you can still feel like crap even if you had all the resources and things you wanted at your fingertips.