I have given 60 days notice to my landlord to move out but now I have changed my mind. Can I be forced to move out?

Depends on whether the landlord wants you out or has already found a new tenant. Also local laws come into play (Any question on law needs to include your general locale as laws vary by area.)

I live in Simcoe Housing subsidized housing in Simcoe County Ontario. I gave 60 days written notice that I was moving out but now I have changed my mind. Can they force me to move out?

Have you talked to the landlord yet?

No not yet. I am in Canada are you?

No not yet. I am in Canada are you?

U.S. laws are different

That's why I asked you were you were originally. I would talk to the landlord immediately. You may be worried about nothing, because they may just tear up the notice. If they refuse to do so, then we can worry about whether they can legally do so.