I have a favor blister and swollen lymph nodes On my right side What do I need to do it just started two days ago but it hurts to open my jaw?

Here is what I sugge. Fever blisters are common but they are self limiting and typically go away within 5-7 days. All you need to do just now is take a pain medicine if the pain is bothering you. Tylenol 2 tablets will relieve the pain for 6-8 hours....so it can be repeated 2 or 3 times a day.
If you are not feeling better in 2-3 days, go see your doctor for further evaluation.