Will i fall out of the big one at blackpool pleasure beach im only 7 stone 8?

Me and alot of my frinds (34) are going to blackpool and im petrified of the big one i have been on infusion and thats fine but i nearly fall out of the grand national :/ im only 7 stone 8 and barley 5 foot to be honest i just need a little re assurance i am really scared