What to do to help heal this? Find another doctor, I'd say. Sure, if someone has a virus and goes to their doc demanding antibiotics, the doctor is within his rights to say forget it, antibiotics don't cure a virus. But if you have painful ulcers on your tonsils, it just stands to reason that there might be an infection going on. Seriously, get another opinion, and if this is your regular doctor, reconsider that fact.
I agree with AnnieBrooke - you need to be seen by a different doctor! And preferably an ear, nose and throat doc! When you have a throat so sore that you can barely swallow, can't eat at all and have ulcers on your tonsils, SOMETHING definitely needs to be done! Did your doc even bother to do a strep test or anything? Strep throat can also cause ulcers in the throat and mouth and strep is definitely something that neeeds to be treated with antibiotics.
I can understand your doc not wanting to give you oral pain meds, since you are already having trouble swallowing and aren't able to eat - you more than likely would hav ea very difficult time taking the pain meds - however, he could have prescribed you a throat/mouth gargle that contains a lidocaine type medication that would help numb your throat and mouth so that maybe you'd at least be able to get some liquids down.
As it is now the weekend, I would suggest going to either an urgent care facility or even the ER and let them know that you've seen a doctor for your throat, he's told you you have ulcers on your tonsils and you are not able to eat or drink. At the very least, they should be able to give you some IV fluids to make sure you're not dehydrated - and probably antibiotics also.
I hope you feel better soon!