Why am I gaining a lot of waight when I have graves disease?

Graves disease is a hyper thiroid.

I am not taking any meds. my weight gain is 50 lbs. My doctor just keeps telling me to have my thyroid taken out.

Ok. But I assume that you are on something like Tapazole to slow it down, right? You might need your dose adjusted. You should call your doctor and have them check your levels.

the meds your taking

What I suggest is talking to your doctor. I don't know what type of medications you are taking, if any at all, but this could be a case of bloating, water retention, it could be some sort of reaction, or side effect.
Without knowing all the specifics of your medications or your specific case then there's not much anybody here can do for you.
Maybe even your pharmacist could be of service to you just to talk about your weight gain.

My girlfriend has Graves disease and she takes medication to slow her metabolism. The problem is the medication might be slowing your metabolism too much. It may need to be adjusted. Talk to you doctor. You medication dosage may need to be lowered. Good luck.

I have seen fluid retention in this disease with swelling of legs and ankles.

You shouldn't be increasing weight. This is a case for the endocrinologist ... a blood test should tell you more.