Hi mark,
You can get this under control and need to take it seriously. It will be with you for the rest of your life.
You don't mention if you have been given dietary advice and a meter and strips as these are the two things that will help you succeed.
...With regard to the bleeding in your mouth, it could be a Vitamin B12 deficiency.
...Cannot help on the medication front but someone will no doubt answer this.
...Your Dr. is probably using scare tactics if he is threatening to dismiss you from the surgery. He would have to get rid of a lot of patients who would have the same problem. Maybe he needs to work out why this is happening to you instead of playing the blame game.
Ask all the questions you need to and let us see if we can get you back on track.
Perhaps you could tell us what you are eating and what your levels are when you test?
Hope this helps,
Catherine.