About A Month Ago I Had Two Red Bumps Appear

About a month ago I had two red bumps appear (one on my thigh and one on my elbow).
They itched and got swollen and red and became painful when scratched. Like I was scratching with needles.
At the time, I thought it was a couple of bug bites so I put a topical anti itch bug cream on it. It did nothing to relieve any symptoms.
The following week, I had two more.
And the week after that, they started appearing at a much more rapid rate.
After I had about 7 at once I thought maybe I had some sort of infestation at home (despite the fact that no other people or animals have had any bumps show up, I'm the only one)
So I bought a couple different kinds of bug sprays (spiders, chiggers, fleas, mosquitos, etc) and sprayed my apartment and washed clothes and bedding.
But I continued to get more and more.
In almost 4 weeks I've had over 30. Each individual welt lasts a couple of weeks.
They don't ooze or blister. They get to the size between a quarter and a silver dollar.
It's mostly limited to extremities. My shoulders, arms, wrists, fingers, legs, ankles, and behind.
Many are leaving behind bruises and red flecks on skin (like blood has come to the surface just under the skin. I think it is probably from when I scratch, which I noted is painful. I feel like wherever I scratch should be bleeding because it feels THAT sharp when my nails go over it (and my nails are not very sharp at all).