Suggest Treatment For Mouth Ulcers After Root Canal Procedure

Question : Hi, a couple of weeks ago I noticed there was a small-medium sized mouth ulcer type of thing on my gum, above my left "fang" (2nd if from front). A few weeks previous to that I had a root canal done on that tooth.
I've had mouth ulcers in the past and they've last no more than a week, and have never changed in size.

Now, this ulcer type thing has grown (I'd say almost doubled its size), but has formed a type of skin tag/flap. The flap starts from where the initial ulcer ended. The best description I can currently think of is that it's "melted" down to form a flap. There's no pain or discomfort, but it does bleed when it actually catches when i brush my teeth. Even then there's no pain. It's just there. When it's not red from being caught, it's a pink-gum colour with a little yellow (like a normal mouth ulcer). I noticed the "flap" this morning.

I don't want to go back to the dentist for this as I do suffer from severe anxiety & a slight fear of the dentist (but I will of course go when required).

I'm really worried and before I contemplate contacting my dentists about this, I thought I'd turn to the Internet. I've never had anything like this nor do I know of anyone who has so can't speak to those about it.

Please advise. Thank you