I had seen studies that say that training or even just daily walks can highly improve mood, but I had never heard that they fully cure depression.

The solution people are commonly offering helps then, even if it isn't a silver bullet. If a silver bullet existed that instantly and universally cured depression I'm sure people would offer that instead. People are offering the best they can to a stranger.

Despite the fact that not all people are capable of doing both.

If you go online and ask strangers, you're going to get general advice. If you have a paragraph of reasons why you can't do both, either, or a modification of the advice of exercise and therapist then I feel for you but aggressively rejecting generally helpful advice while looking for some other solution is putting the responsibility on random strangers to come up with something.

I'll add that while some people may not be able to do some of the common advice, I privately suspect that at least a healthy percent of the time that resistance to the advice isn't coming from inability to do it, or in the case of the exercise part to follow the spirit of the advice by being more active. If you truly have a chemical imbalance, a therapist is the person who can help and is qualified to talk about drug solutions.

Short of telling you to see that therapist to get actual professional help, and doing exercise which while it might only a partial solution is something that you can do right away, what exactly do you want of random people?