Unity engine is slow in game mode

I am a unity noob and i have been working on a game and recently it has been really slow when i play the scene in the engine it runs at about 0.5 frames per second but in the build it works fine. It used to work at 40+ frames per second but i dont recall what would have caused it to become really slow. Is there anyone who has had a similar problem and solved it?

Hey I had the same problem(accept I noticed a performance drop when trying to move large distances with the editer) I made two of the same name controls under project setting+input

If u did the same u have to rename one

If this is not it then it may be a similar issue

Hope this helps also if it does I have a question that requires Somone with scripting skills check it out if ur interested

i solved the problem it was because i tried to add a script to the terrain and the character that didnt bleong thanks UNSCspartan500