I have a feeling you are using an UTH stuck to the side of your tank?
Not the best choice for the husbandry of your snake.
You can try to remove the heater but slow and gently.
Most of the time you will damage it removing it but they can be taken off without damage.
Either way, next time get some aluminum foil tape and make the mat easy to remove.
To do this you will lay the mat on a table sticky side up and cover it with foil tape sticky side down. Now you will just use a couple pieces of foil tape on the edges to hold it in place.
Dont forget to get a thermostat BEFORE you put your heat mat in the better location.