Just keep the burnt area clean. Bathe and dry up with a cotton towel. Unless you are a diabetic or other medical conditions or if you are pregnant or if you are on some long term medical treatment, you need not worry.
It is also important to take adequate rest (especially to the affected arm). Keep yourself well hydrated and dont worry about what kind of foods to eat. There is no bar.
For pain, use any anti-inflammatory (take them after food). Please consult your family doctor for treatment since this is a web based interaction and some points may be missed. Next time, it is important to post all medical details by medical opinion seekers on the web. I urge, "healthcare magic" to have a form or questionnaire filled up by people who are seeking answers on the web. There should be a proper "flow chart" like questionnaire which helps in giving qualified answers to the patients and also educates the patients.