I gave a moveout notice but have come to realze I don't have the strength to pack. I want to cancel my moveout notice. Can I do this? Do I have the right to do this?

No.

Read your lease but I'm sure you can't - you CAN negotiate a new lease and remain if the landlord consents.

You have to talk to the landlord to be certain that he doesn't already have a replacement tenant lined up and to see if he'll renew your lease.