Hey buddy,
You are not alone in this. I am also a few years younger than you but have always had this surgery in mind. I remember the first time I heard about it was when I was 17/18 and I thought w t f, do people do this?
I also feel I have the same problems with my parents, actually I have only told my mum and recently my younger brother and they both think I am absolutely ludicrous. Convincing my dad is almost impossible. He will just not understand but I have made up my mind and will do this with or without his support. I am yet to inform him but this is inevitable. Maybe if I pus*y out i'll get my mum to tell him lol.
But I will say to you what I say to my family: the technology has improved a lot! Nevertheless, I also have concerns like your parents whether my legs will be the same post surgery. To be honest, I am doubtful that they will 100% like now, however, I am extremely motivated and will do whatever it takes to ensure my post LL legs is as close to my current ones.
Lastly, if your height really bothers you that much, just do it! As long as you do it safely.
All the best, friend.