1992 Cadillac Eldorado Sport Touring Coupe

Dear Sirs, I bought this vehicle three weeks ago. It had been parked for the past four years. It has 133,000 miles and powered by a 4.9 liter V-8. I put a new battery in it along with a tank full of premium and it fired right up. It runs excellent. The motor is very strong. I then changed the oil with synthetic oil, and replaced the oil filter along with the air filter. I then drove from Las Vegas to Phoenix. The air conditioner did not work, so when I got to Phoenix I checked the fuses and replaced the relays for the blower and A/C compressor. The clutch on the A/C compressor was not kicking on. I then oil charged the system and added freon. It still did not work. I crawled under it and pushed on the electrical connection going to the compressor. It now kicked on. After driving it a mile or so, the engine temp. Read 250 degrees F. I then pulled out the 195 degree thermostat and could only find a 180 degree thermostat for it. I flushed the cooling system and added a 50/50 ratio of anti-freeze to the radiator. I also bought a new radiator cap, and installed it. (16lbs. Cap) throughout driving the next 200 miles, the A/C would come out of the bi-level vents and change to the front windshield vents on its own, all the while it would stop working all together. I would pull over, wiggle the electrical connection goint to the compressor and it would work till I hit a few bumps. It will no longer come on. I pulled the serpentine belt and checked the compressor to see if it froze up. It still spins. Also, my engine temprature would run between 200-232 degress F. I dont have alot of money and my tools are limited. I am miserable driving to and from work, as the daytime temp. Is averaging 110 degrees F. Is there a special anti-freeze called dex-cool that is supposed to be in my radiator? Along with a sealer from Cadillac? It says nothing of the sort under the hood anywhere. I just used Peak. Could this be part of my problem? Also, the clip for the electrical connection going to the comp. Looks as if somebody rigged a different one on. There is also a white plastic thing that both of those wires go through located about a inch from the clip. Is this supposed to be there? If so, what is it and what does it do. I don't know much about cars but it seems to me that the electric cooling fan is not working proper. Is there a way I can check this? As you can probally tell, I have a mess. Working with limited knowledge and funds does not help. Im not stupid, if you explain to me what I should do, I can follow instructions. I will be able to make a donation after the 8th of next month. That is when I will receive my first check. "PLEASE HELP" Thank you in advance, peevola