Thank you for submitting your question. I would recommend finasteride. PRP, laser cap and amino acids. When you are ready for your FUE, approx. 1500-2000 grafts would help create more density. Best wishes.
There is nothing you can do about your sun burn other than keep out of the sun or wear a hat. The grafts themselves, have a skin that came from the back of your head and never, never were exposed to sun so this skin is easy to burn.
You might have an infection in the recipient area. You must see your doctor and get it diagnosed and treated or there is a risk of damaging your hair growth.