Is my board too small

Hi guys. Love this forum.
I really want to start surfing. I have done a couple lessons an read on here that I should try and get a second hand board. I'm 6ft 1" and 95kg at the moment. Hoping to shed some o this surfing. The second hand board I got is a 7'9 bic natural surf. Is it big enough I got smashed about today but te surf was pretty large. It just has one big fin. Shop owner suggested I get an 8'4 but that would have been brand new. Please tell me I'm just being negative and that I should be able
To learn just fine on it
I really want to start surfing. I have done a couple lessons an read on here that I should try and get a second hand board. I'm 6ft 1" and 95kg at the moment. Hoping to shed some o this surfing. The second hand board I got is a 7'9 bic natural surf. Is it big enough I got smashed about today but te surf was pretty large. It just has one big fin. Shop owner suggested I get an 8'4 but that would have been brand new. Please tell me I'm just being negative and that I should be able
To learn just fine on it