Looking for support, both my parents have been diagnosed with Parkinson’s

I’m really struggling to grasp how this could happen. There’s no history of Parkinson’s in my family on either side - yet both my mom and dad have been diagnosed. My mom was diagnosed at 50, my dad at 60. My mom’s is much worse but she’s a fighter and exercises 3 hours a day. My dad is not as advanced, but he’s not fighting and I can see it going downhill rapidly, he’s getting stiff and isn’t fighting it. Mom’s a shaker, dad’s turning into a statue.

I feel like I’m a ticking time bomb. I’m convinced that they must have been exposed to something that caused this. Something I was probably also exposed to. Pesticides maybe. We had a bad year with grasshoppers one year like 15 years ago and my dad got some crazy pesticide spray gun and went crazy with it with no mask. My dad’s mom lived to 98, my mom’s mom is still alive perfectly well. My grandfathers both died from chosen vices (lung cancer/alcoholism).

I know life is not fair but I can’t help but scream at the top of my lungs. I don’t have kids yet but when I do they probably won’t have grandparents. At least from my side anyway. Who is going to even going to want to marry me at this point - my genetics are undesirable :(