I’m sorry to hear that you are suffering from this for the last 2 years. From the pictures, it does not seem to by a typical acne cyst. It may not even have been a pimple right from the start.
I would suggest quickly seeing a dermatologist for your condition. There are various ways of removing this lesion which has good cosmetic outcomes. If necessary, he/she may also suggest sending the lesion for further testing depending on your consult.
Hope this helps!