Fan out of control and slowing computer

[DTR100]

I have had my Macbook Pro for a little bit over a year now and I have been having problems with the fan. It is running at very high speeds and slows down the computer to unusable speeds. Now it will stop but only for a little while if I put the computer to sleep and then wake it up, but it always starts again not ten minutes later. I am using Firefox. I also downloaded SMC fan control for my computer becasue it was getting very hot, but it is uninstalled and it has been for about two months. I just need to know how to fix it please. (I am pretty sure that the SMC fan control caused the problem.)

 

[simsaladimbamba]

Open Activity Monitor and select All Processes and then sort by CPU to show you the process(es) slowing down your Mac and speeding up your fan(s) and causing more heat.

Using Activity Monitor to show you CPU and RAM usage​