Ulcer after throwing up- ideas for treating?

Hi All

I had a case of food poisoning last thursday, i threw up maybe 5 times over 24 hours.

That's all calmed down now, but i had the worlds biggest ulcer on the roof of my throat the next day ..the first ulcer i have had in months!! It feels like half my mouth is an ulcer.

Four days later it doesnt seem to have improved, i guess the radiation treatment makes healing from this stuff slower, but i am just wondering what you guys use?

I am sticking to soft foods, and doing regular salt water washes, and trying to protect it with alclair, but it doesnt seem to be helping, any ideas on what to try? i have considered difflam but its pricey.

Thanks