So, as the subject says, I'm stuck in a weird phase of my surfing progression right now. I have been surfing for about three or four months, and I'm having some trouble with what steps I should take next to up my surfing level. I live in Southern California.
I started surfing about three or four months ago on an 8' x 22'' x 2' 5/8'' minimal. I like to think I progressed quickly, and was able to stand up within 4 or 5 sessions of surfing (at beginner breaks such as San Onofre and Doheney). In favorable conditions and wave size (2 or 3 ft max) I am able to down the line both backside and frontside, as well as do a pretty cool bottom turn. I am able to catch most waves as long as they are not too steep.
Quite possibly getting ahead of myself, I bought a 6'8'' x 21 x 2'7/8'' fish, thinking that I would be able to use it with my plethora of skills acquired in three short months. However to my surprise, I find myself struggling and getting a bit discouraged on the fish. I am not able to stand up. Wave positioning and my pop-up speed on the fish are something that I need to adjust to. So my question is, seeing as though the minimal seems a little easy to ride, and the fish is a bit difficult to ride, what should I do? Should I stick to the minimal for a bit longer until I get better, or should I tough it out on the fish, and get acclimated with the shorter board? I am very hard on myself for not being able to get up, and get very discouraged


**Extra info: I'm about 5'9'' and 160lbs. I like to surf Bolsa Chica, T-street, Doheney, and when I can San O (it's a bit far from me)