Difficulty in swallowinf with mouth ulcers may be sue oesophageal and oral candidiasis which common in hiv infected persons. Tou can for oral medication therapy of fluconazole if able to swallow.....if ot more sever then parenteral therapy with amphotericin B is indicated. In oral cavity there is a white coating not going with bruahing and cleaning and bleeda on removing part of it then it is oral candidiasis....mouth paint containing anti fungal agents like candidouth paint is advisable if tjere is only oral involvement.....for burning in mouth and ulcer you can use analgesic and anaesthetic lotion....vitamine and folic acid suppliments can be taken with it....as you have not mention about anriviral treatment.....you are not taking then candidiasis is eligibility criteria to start anti retro viral therapy....go to nearby infectious desease clinic and get it start