Planes and ha

Im due to go no holiday on friday but like many of you guys on here im convinced I have some sort of tumor growing inside me or that im gonna get a blood alot in my body somewhere. Im getting super anxious now about whether or not my flight will have any effect on me . Like if I do have a brain tumor or leg tumor will they be effected by the pressure change? Im going out of my mind its one thing after another :'( I just wanna enjoy the holiday yet im thinking stuff like this. I don't wanna die :( xx