First of all, your English seems quite good. And English is a difficult language, especially the grammar. I wish I could express myself in Mandarin as well as you just did in English. Please don't be too hard on yourself. We're not language monks. The point is to communicate, and if anyone gives you a hard time about your ability while you're making a good effort, I think they probably need to get some perspective.
It's true, people are hesitant to make corrections. For one thing, although what you said might not have been completely correct, it was perfectly understandable. Another thing is that they might not know how best to make the correction without hurting your feelings or seeming pedantic. You just can't count on people to correct you.
One useful thing I did lately was to get on WeChat and start chatting with my Chinese friends. Many lines they send to me are goldmines of useful expressions, expressed naturally. Slowly but surely, I'm building up an arsenal of fragments I can use in situations that come up a lot. And I think each little fragment I master tunes my neural network to make learning the next fragment a little bit easier.
You say you can't learn from audio/video courses. I hope that's not true. I would think very carefully about why it's impossible. Maybe there's a way, and if there is, that would very very very useful.