Grammar check, just one sentence.

It's fine. I would probably say when there rather than whenever, but I can't explain why. When sounds more natural to me there.

It feels a bit wordy, but it is clear enough and I understood it easily. I might have worded it looks this: > I love it whenever I successfully and clearly express my intended thoughts in English. I turned "succeed" into an adverb so that it matches "clearly" and so that "express" can be the focus of the "whenever" phrase.

I feel confident when I am able to express my opinion clearly.🤪🤪

When describing an action, you would use 'succeed at' instead of 'succeed in'. So, "I love it when I succeed at clearly expressing my intended thought in English." If you are referring to one thought that you expressed in english, this is fine. However if you are talking about how you feel getting several translations right over a period of time while learning English, I would instead go with "I love it whenever I succeed in clearly expressing my intended thoughts in English". This sentence tells me that you try to express yourself in English often and that you enjoy it when you succeed. If I were to say this phrase colloquially I would naturally say "I love it when I can clearly express my thoughts in English", replacing 'succeed' with 'can'.

It's a bit long and could be clearer. How about simply "I love being able to express myself in English!"

Sounds fine. No errors. I myself would say "I love it when I manage to articulate my ideas in English."

It's fine.

No errors, but certainly a little verbose and formal-sounding. Native speakers will tend towards more economy of phrasing: "I love it when I manage to say what I mean – in English!" or something like that. You certainly succeeded in clearly expressing your intended thought, though!