Surfing Waves

I am 57 years old, 87kg... started surfing about 4 years ago. Having great fun on my 8" soft top. For the mediterranean waves where I live it is a great fit most days... Also got an 8' funboard, i can surf with it but I struggle which takes out the fun of it sometimes... so considering my age, what do you think, should I hang in there and try to improve on the fun board?

What do you mean by struggle. Describe the problem better.

The big difference between a soft top and a fun board of the the same size is the flotation of the soft top is a easy catch wave barge compared to a fun board, Fun boards are a little less paddle friendly but penetrate white water better, and fun boards require a more precise learning of techniques being less forgiving. However as. OMS said knowing the precise nature of your struggle might help us advise you on how to fix it.
Softer? mediterranean wave might need different approach.
Where do you surf?

Funboard is about 17 liters less volume, so I need to generally work harder, including paddling, catching the waves and balancing needs to be more precise...so it is just harder. Another one is that I feel very comfortable on the lineup next to other softies... and more confident, it is different with hard top. In addition we had a tough winter here, no waves so got out of shape, spent more sessions on the softboard.
It is Tel-Aviv. So tomorrow we have half a meter, 6-7s waves... I know that on the soft one I will have fun... but should I take the funboard and catch less waves...

No unless it is fun to not catch waves don't use the funboard, Maybe look at getting a longer board or just stick to soft one. However it takes a little while to get used to having less board. When I was relearning to surf after not surfing for 12 years I dropped a foot and a half in size to a funboard and I couldn't even lay on it well and frequently slipped off the side of the board as it was far less stable so I ordered a longer funboard but before it was made I adjusted to the shorter board. It took me about 6 sessions to get used to it. If you have only used it once it might be good to keep trying. For one thing the shorter the board the more exact you have to be in placing your body on the board to paddle it. you want to have the tip of the board an inch or less out of the water while paddling. The other thing is you need to be more exactly in the right place in the lineup to take off on a wave

A much quoted quote is; The best surfer is the ones having the most FUN!. Stay soft enjoy or get a 9ft longboard and progress.
There is enough going on around you……. go have fun, if you want an improvement curve do 9ft