Your doctor should have discussed all this with you, but HRT is currently a forever thing almost always, because they do not really know yet how to jumpstart testosterone production consistently. If you have secondary hypogonadism - and, sorry, I can't remember your LH/FSH #s - then, theoretically, you may be able to get jumpstarted.
However, this just does not seem to happen except in the case of steroid users as far as I know. One of the reasons, I suspect, is that it is often due to the fact that the hypothalamus is damaged. But, again, no one is studying the 'why', so solutions will be awhile.
You can go off of HRT, but it is generally painful and takes many months for your body to recover to where it was at and, of course, your back at square one with low testosterone.
Talk to your doc and confirm, but, with the exception of some steroid users, I have not seen men "healed" or "cured" of their low testosterone. FightLowT's doc actually tried that with him and it did boost his testosterone temporarily but then it fell back down. If you're interested, you can read one of this first posts on the subject...
NOTE: You can kind of "shift gears" and go a new form of therapy. For example, you can go off of HRT and do what some men to preserve testosteorne and fertility, such as Clomid/HCG. But I don't think that is what you are asking here, i.e. can you quit HRT cold turkey and/or can your body heal itself over time? One final comment: men who lose a LOT of weight can in some case turn their testosterone production back on. But that does not apply to you either.