Upstairs neighbor in condo 'harassing' me

I bought a small, 1br 700sq ft condo about a year ago. The walls are extremely thin and the people above me have fake hardwood floors. I work from home, but I'm out of the condo at least 4-5 hours a day doing stuff. I assumed that the person above me had a job or at least left the house every so often. A couple days after I moved in, the person above me started to literally yell loudly if I did something not to their liking. If I ran the faucet too often, the person would yell stuff like "GO AHEAD, GET ANOTHER DRINK OF WATER!". He stopped doing stuff like that, but he still harasses me occasionally. Sometimes, he will follow me around and drop stuff right above my head. If I do the dishes, he will start bouncing a ball right above me, then when I go to the bathroom or the next room, I'll hear him walk over also and start doing it in that area. It's like this guy is obsessed with me.

Also, every single morning, I get woken up at 3, 4, and 5am on the dot by him dropping something extremely heavy directly above my bed, or stomping loudly with his shoes on the faux hardwood floors, while I'm sleeping. This person is so crazy. I don't even think he sleeps. He never leaves his place and doesn't have a job. Also, he chainsmokes in his unit, because my place smells like smoke non-stop, and I have allergies because of it. I know it's him, because I know the people on the other sides of me, and one of them doesn't smoke, and the other person does it outside, and the smell from that goes away within minutes, because of the wind and air. But the person above me must smoke with no ventilation or anything, nonstop. All my clothes and everything in my unit smells of smoke. I light candles and have 2 air purifiers, but they don't even put a dent in it.

But the main thing is the person stomping and dropping stuff above me, every morning/night, at 3am, 4am, and 5am, on the dot. I have no idea what this person has against me. I guess they're just pissed off because someone bought the unit below them, after it being vacant for 6+ months, and because they don't have completely privacy. This guy just never, ever leaves. He hasn't left in 3 days. Every time I come home and see his car in the parking lot, I get depressed. I've literally only seen him a handful of times in the parking lot, while leaving or coming home. I just say hello, and usually he doesn't even acknowledge me, or just says "hi" back. It's so bizarre. I put the condo back on the market, literally a month after moving in, and still haven't found a buyer. I'll probably lose between 25 and $30,000 (I didn't do enough research and overpaid around $20,000 more than it's actually worth), but I'm willing to take the hit to get away from this lunatic. I'm literally afraid of this guy, and I can't relax at all.