Board size. Is it too big for me??

Hi all, I'm a competent surfer, I've surfed on and off over 10 years, just got fully back Into it. I'm around 5ft10- 11 and about 67kg, I brought a hybrid semi performance board,it's 6ft 20 inch wide and 2 5/8 thick. I haven't taken it out in anything over 3ft yet. But I'm struggling to manuover it. Does anyone think that 32.5L is too bouyant for me? When I try and dig the rail it feel like I'm on a trampoline n it's bouncing me back up. I've rode boards fr 5ft 4 up to 6ft 5. (I've never been able to surf long boards or mini mals NEVER been able) I learnt to surf out the back on like a 6ft4. I only got the vessel dark horse at 6ft 32.5l cuz I'm getting older and not as fit. But did I make a major mistake?? I'm thinking I should have got a 5ft 8 but too late now. N I just need someone to make me feel better bout wasting $650 lol but honestly should I be able to carve/rip it up on a baord with say 2 - 5 more litres than I actually require??? And also I'm using thruster large fins (which was a mistake I asked for medium) sorry bout my life long story!