I think I know what is going on, based on the symptoms you describe, but it is impossible to be certain over the internet. The best thing to do would be to go see your regular primary care doctor
, who should be able to take a good look at your eye and provide you with an accurate diagnosis.
Based on the description of a swollen "bug bite" like lesion on one eyelid, the most likely diagnosis is a stye, which is blocked gland at the edge of the eye lid. Styes are very common and, fortunately, usually fairly easy to treat with simple measures like warm compresses and good hygiene. Sometimes, more serious cases may require antibiotics, although this is rarely necessary.
Another eye condition that your doctor will consider is blepharitis, which is a more generalized inflammation of the eyelid and which seems more unlikely based on the description in your question.
Your doctor will help you figure out if any specific treatment, such as with antibiotics, is indicated at this time. They will also be able to provide followup for the condition. Most styes, if this is what you have, will get better within a week or two. However, if the problem persists for longer, you may need a referral to an eye doctor
, and your primary care doctor can arrange this for you.