Extreme health anxitey

Ok so I have Gad but with that a have extreme health anxitey in the last 5 weeks av convinced myself I have a brain tumor , skin cancar , cervical cancar , ovary cancer , breast cancer , heart attack .  Am only 19 and are so depressed a don't even want to wake up because a know am going get some sort of pain and worry about it all day x a can be told told by 100 people that am fine and then 1 person tells me it could be something a panic  am always getting my bf to check my boobs for me like 3 times a day cos am convinced am going get cancar no matter how many times am reassured a don't believe it x  a do t even want to have a shower incase a see something that sets me off x at this stage a dread each day a just lie in bed waiting for the day to be over !! Any advice or has anyone gone through this x