I'm very afraid of cancer,help?(this is dressing the heck out of me)?

Please bare with me or this is bound to be long...

I didn't use to be afraid of it, let alone think of it, ever. Since last summer or so i've been getting on and off episode of cancer fear. My sister tends to talk about how cancer runs in the family how dangerous it is for us and my mom sometimes does too. And sooner than later this got to me. It started to work up in my mind and now I realize that I'm terrified of it. I have many ambitions and within 7 months i star college, what i consider finally starting my life. I have high expectations of it, I know i can be someone great at what I love doing but... the fear just won't let me enjoy it, rather more it makes me feel sad about it. Why? because I start thinking about if i get cancer my life could be cut short and I won't be able to achieve those dreams. I'm not afraid of death, I've come to terms with death, what I am afraid of is of dying before being able to accomplish my dreams.

This has me very depressed and discouraged. I don't know what to do.

I know you might say "get your mind off it" or "just ignore it". I've honestly tried. I've also tried talking to my mom about it but she says to not be afraid, It's just not easy.

My great grandmother(from my father's side) died of cancer, so did my great great father(mother's side),my great aunt recently died of breast cancer, they all got it after 50 years old,but my step brother (form father's side) died of cancer two year ago and he was in his early 30's, and my long time childhood friend has cancer. So all this things have gotten to me.

Also,one time my sister was having an endoscopy due to a none-related cancer case but during the endoscopy the just happen to find a tumor and just removed it,she was never told of the nature of this tumor, nor felt it(i think it was in her stomach,I'm not entirely sure where) . She even said "imagine what could it have been if they wouldn't have seen it in the endoscopy"

It scares me and saddens me so much to think that someday I could get cancer too. I don't care too much if i get it when I'm very much older and have accomplished things and had a family but still I don't ever want it in my life,ever. Even if older I wouldn't want it in my life,that I just said is under my "acceptable" parameters.

I've been hearing a lot about cancer "cures" advances like the "moonshot" and such but honestly, it there's another things that scares me and it is greed. I'm afraid that if they do find a cure they won't say it or won't use it all 'cause of the money they get from alternative methods and such.

I use to be more optimistic when my fear began, I'd say "if i do get it then by that time there will probably be a cure anyways"(and yes i do know cancer is a umbrella term). I'm just 17 years old, soon to be 18 and honestly this is destroying my young life.

I know you'll think I'm hypochondriac and who knows? maybe I am but I'm not here for a diagnose. I would like some help if any you can proved. yeah, i know I'm asking random people over the internet but that's just it, You're all people who have gone through things and I never know who might surprise me actually help me.

I know I shouldn't waste my life thinking about stuff like this and just live, but it's always in the back of my head hurting me. Maybe I can somehow somewhere along the line let go of the fear but it would only be temporal and I'd still think about it every other now and then, as it has happened before. But this time I feel is much worse, yet I'm luckily sleeping at night.

Can anyone please help somehow? encourage or give hope? idl, anything t hat may help.. and please don't go pointing out that I should got to a form of mental and or spiritual help. They are somewhat already in consideration.