It probably doesn't get you an absurdly-high-paying FAANG job rewriting code someone else rewrote the year before, but I guarantee you any competent generalist in IT can get well-paying job without much trouble. There are a lot of places out there that can't afford to have a specialist in everything they do, but can afford the kind of person who is willing to tackle any problem put in front of them.
I hope what I said makes sense. Try not to feel frustrated. Frustration never helps.
If you don't enjoy it, find something else! If you hate it so much that it makes you suicidal, doubly so. I tried doing the "practical" money making thing, and it made me miserable. Programming is the thing I found later that brings me joy.
Find what brings you joy, and do it. Until you know what that is, explore. Hop on a bike and ride across the country. Move into the woods. Go volunteer in a developing country (some positions provide room and board, you just have to get there, but the pandemic does complicate things). Literally anything other than 1) what you are currently doing 2) suicide.
I have been there and I feel for you, truly. No matter how it feels, there are other options. Take care of yourself and hang in there. From someone that has been to the very bottom and made it back, it can get better.
What do you do now?
Another issue is that it's entirely possible that your current role doesn't challenge you to learn or retain CS concepts nor deeper aspects of the practical tools you use. Many jobs can be done very well using the same shallow toolkit repeatedly. If that's the case, it's not really a question of your ability, but maybe you can start actively looking for projects to force yourself to start learning more.
Employees are an investment. An employee who can take the initiative to flag-up areas that they could benefit from training is valuable.
Not having deep knowledge on particular subjects, not knowing OOP, being a generalist - these are not signs of being "terrible". Everyone has blind spots. Some people work on font rendering or audio codecs their whole careers and don't know how to build a decent web app to save their lives. That's ok.