Really just a cyst or even a tumour?

Hey dear community, I have visited my doc (expert for mouth and tumours) half a year ago to take a look at some issues which I had. First some weird pimples which I had all around my mouth mucosa for like over a year and some weird little white bump on my hard/soft plate. He too a tissue of my mucosa because he thought it would have been an infection. But the test said it wasn’t one either. So I still have this weird irritations on my mucosa. So to the bump he said it would be a cyst so he cut it out, just leaving a big hole behind. But I’ve noticed that a little string of muscle maybe from the supposed cyst was left in the hole but I didn’t dare to touch it. So after it all had healed properly I’ve started to smoke again and noticed that the bump was growing back. So I thought to myself “The doc said a cyst is a capsule filled with fluid” So I carefully stitched it open and some weird tasting fluid came out and the bump shrunk back. But now a month passed and I’ve noticed that it got even worse and bigger. Now it gained form, having something like a tip or pimple in the middle. So is it possible that a cyst grows back? Because I read alot of articles which claimed that tumours used to have such a weird form and white spots. Plus it feels very weird and hardened. Please help me I’m pretty concerned and unsure if I should visit another doc for a examination. (Ps: sorry for the grammar flaws, I’m not a native english-speaker)