Is my longboard a good size for me?

I know this question has so many variables but I wanted to get some feedback from people who have been doing a lot longer than me. I am a beginner/intermediate who has recently got back into surfing after 10 years of absence due to moving away from waves. I used to surf on a 8'6" hybrid. Im back now on the coast and bought a 9' pearson/arrow formula 1 because i thought it would be fun and better on small days. It is 22.5 wide and 3" thick in the middle with thruster fin set up --6" middle fin. The guy at the shop told me this was the board for me. I am 6'1 and 200lbs. Anyway, I have to paddle a lot harder than I thought i would to catch waves and in general seems to not be as buoyant as I was hoping. I do get up on it and its fun and very responsive. Is this just me shaking off the rust or I am wondering if I should have gotten a bigger board? Thanks in advance for any feedback.