Help! Engine won't cut off !

[Mattdeacon1]

Hi all, I have a 2003 forester xt, my engine will not rev past 2000rpm and when at idle it almost cuts out and revs itself ect, 

the engine will not shut off when I turn the key and take key out ( is fine when starting engine) and there is a faint smell of burning underneath the steering column, to make the engine cut out I have to take the leads off the battery 

 I am guessing that the two things are related, the main 100 amp fuse blew before all this happend which has now been replaced and hasn't blown the new one