I Have Had Major Skin Changes Since I Was 17

I have had major skin changes since I was 17 I am now 30 this started out on the backs of my arms only and now I'm currently dealing with it on my arms my thighs my hips. They are usually in the form of a bump with either a hard piece inside usually a yellowish color similar to blackheads. Other time is I scrape the surface of the bump it's a dark sometimes thicker hair. Most recently the ingrown hairs are around my pubic region and bikini line and even form in the crevices of my stretch marks (the bumps near/within my stretch marks become very big and red but produce a very thin hair) almost every body part has some sign of whatever this is. My skin is very tough so when I bother or try to pluck them I cause sores and my skin is very very slow to heal. I was told once I had follicular dermatitis I took meds and tried several different expensive antibiotics but it did nothing but make my skin oily. Please help!