That level is a bit higher than what would be considered textbook primary or secondary low total Testosterone, however good TRT follows the symptoms. If you have low Testosterone symptoms, they started at a certain point & have not improved, and very little else has changed in your life - It's likely that you could be suffering from relative hypogonadism. We have treated many men in the range that you are in now who presented with classical symptoms & durations. They all feel better now that they are on TRT.

For coming off TRT your levels (completely cold turkey) tend to return to previous values in 4-6 months on average, though in some can take up to a year. Assisted cessation (adding ancillary meds like hCG and SERMs), can shorten recovery to baseline to as fast as 3-6 weeks.

Getting on TRT does not typically lower natural production capabilities in the future if you need to come off, though anecdotally people do report this after they have been on TRT for years. The thing about that is you always lose Testosterone production potential over time. If you're on TRT for 10 years, you'll return to your previous levels however what they would have been for a 10 years older you. It wasn't really the T but the age that caused on an issue.