Car won't start after overheating. Possibly added coolant incorrectly?

I was driving my car the other day and suddenly the temp needle shot way up to the red so I pulled over and let it sit for about an hour to cool down before trying it again ad it started up but after a few min of driving the temp needle went back into the red so I pulled over again and looked under the hood and it seemed to be spraying antifreeze out of the overflow tank. After letting it cool down again I tried drivin it again ad this time the temp needle went into the red but then suddenly dropped down to cool so I continued driving and once j started going uphill it lost power and died. After about an an I was able to drive it far enough to get it home but couldnt get it to go any faster than 80kmph. The next day it wouldn't even start. It turns over but won't fire up. A while ago I added coolant to the plastic coolant tank like on most vehicles but thn noticed a sticker on the frame (hidden under dirt) that said that this car requires a special process to add coolant and not doing so could wreck the engine.