Almost nobody loses their accent as an adult, and almost nobody needs to. What matters is not whether you sound foreign but whether you are easy to understand — and those are two different problems with two different fixes.
Accent and intelligibility are not the same thing
A strong accent can be perfectly clear. A mild one can be hard work if it lands on the wrong features. Listeners forgive an unfamiliar vowel colour; they struggle when stress falls in an unexpected place or a syllable disappears. So the question to ask is not “do I sound native?” It is “does anyone have to ask me to repeat myself?”
Fix the few things that carry meaning
Worth the effort: word stress, sentence rhythm, and any pair of sounds your language does not distinguish but the target language does. Those cause actual misunderstandings. Not worth it: chasing a perfect version of a sound listeners already understand. That effort buys you a marginal improvement in how native you seem and nothing at all in being understood.
Get feedback from confusion, not from opinion
The useful signal is the moment someone looks blank or repeats your word back with a question mark. Note what you just said. That word is on your list. Asking “how is my accent?” mostly gets you politeness. Asking someone to tell you when they did not catch a word gets you data.
An accent is a fact about where you learned to speak, not a defect. Aim to be effortless to listen to, and let the accent stay.