your vocabulary is fine. your active vocabulary needs to grow. that's why you can passively understand most of what you read and hear. your production of the language is what you need to improve.

that's practice. Speak as much as you can.

I teach English as a foreign language and if any of my students wrote the same way you do I'd cry with joy. You have no problems with accuracy but if you're having trouble speaking then it's fluency you need a hand with. Conversation classes would be a good place to start or as someone mentioned just chatting to someone over the phone or zoom.

Also if you really want to expand your vocabulary, try learning lists of phrasal verbs. Even my most advanced students find them difficult, but native speakers use them all the time so it helps with understanding and will make your English sound more natural.

I don't know what language you natively speak, but I would love to learn! Pm me if you're interested and we can call and just talk. That's typically the best way to learn the finer details of a language, just speak with a native speaker regularly. As far as grammar and vocabulary, though it doesn't always show in my comments, I'm quite adept.I also used to be a tutor for a ton of people, although I never taught anyone English, so I'm quite good at teaching and communicating as well.

I recommend reading with a Kindle or other e-reader so you can look up unknown words as quickly as possible.

On the kindle paperwhite, pressing your finger for a couple seconds will pull up the dictionary entry for that word. Sometimes instead of the dictionary it shows the wikipedia article entry if it’s a proper noun.

I read in Spanish on my kindle paperwhite because it’s about 20-50 times faster to look up a word on the screen than it is to switch to a physical dictionary.