I have a pitutary brian tumor and I have been taking Levothroxine...

I have a pitutary brian tumor and I have been taking Levothroxine for about 7 years and I need to know what happen if you quit taking this pill? I have been thinking about it, to see if I feel like my old self again. I am only 38 and I have extreme about of hair loss, hungry all the time, dry skin, no sex drive, no memory, the shakes, weight gain and can't lose any. I have been the same weight since the removal of the tumor. Ihaven't lose a pound and haven't gain a pound but I sick of being fat and can't lose a pound. No matter what I do. And I am always tired . I sleep about 90% of a day. I am to young to feel this way everyday. I feel they should of left the tumor in there so I could of still been myself for a little longer. Than to live like this each day. I just want to know what will happen if I quit taking this Levothyroxine? Let me know, please. Thanks!