Last year was a pretty crazy year for my wife and me - said goodbye our two dogs of 16 years, I switched companies and got a huge pay raise, and we sold our first house.
Both of us got CoVID at the beginning of the year but recovered fine. My wife suffered from depression as a teenager and suggests that I should consider seeing a therapist as it helped her but I don’t even know if what I’m feeling is depression.
Searched to see if anyone asked if you've had COVID and found you volunteering that you had. This is very likely to be the cause of your problem.
You most probably haven't recovered fine, and I'd recommend discussing it with a doctor. I've been dealing with COVID aftereffects since early 2021. It's insidious and very, very real.
Edit: Until you've verified that post viral syndrome is not the cause of your problems, please IGNORE all the advice people are giving you to exercise. If you have post viral syndrome, your return to exercise needs to be very slow. Graded over months, not weeks. Overdo it and you'll regret it.
Further edit: In case it helps with googling, the symptom you may be experiencing is medically referred to as "brain fog" and the risk with over exercising is experiencing "post-exertional malaise".
I think seeing a therapist sounds like a good idea. If you don't know what it is you're feeling a therapist can help with that.
To you're original question I'm sure you can still learn, it's just that you can't, at the moment, learn what you think you should be learning. There's undoubtedly a complex mess of social and physical and psychological reasons behind this. Doing the work that's required to understand this mess and find a way through is hard but you can do it. Take care of yourself.
Both of us got CoVID at the beginning of the year but recovered fine. My wife suffered from depression as a teenager and suggests that I should consider seeing a therapist as it helped her but I don’t even know if what I’m feeling is depression.