mental health struggle

i’m 16 male never been so anxious in my life for the last 4 weeks i found a changed mole on my head and the next day movable lumps in my neck i went to 3 docyets and they checked the mole and lump said it looks fine and on my age i shouldn’t worry anyways but iv been so worried about it spreading to my brain and last night while watching a video about a brain tumour i can’t really explain what happened it’s like i blacked out and woke up like iv been in a dream and im scared its a seizure the falling was like if u doze off