Having a difficulty moving to a shorter shortboard

Hi everyone. I'm new here. 
I'm 5'9", 165lbs, 24 years old and still fit. I'm from Thailand, living in Australia where my local surf is below-average/average quality with 1-3ft height normally. I started to surf one year ago and nearly all the time I've been surfing my dear old 6'4 standard shortboard. I learned on this board so I'm very used to it. I surf at least 2.5-3 hours nearly everyday and I'd say I'm an intermediate. I like my board, though I feel that it's not agile enough for my local wave size. So, after researching and thinking about it for a while, yesterday I bought a new board. It's kind of a hybrid shortboard/fish and the length is... 5'10
. Yeah, there's a big gap but it's still a bit taller than me and I am willing to ride it!
Here is the picture.
My new board - 5'10, 19"3/8, 2"1/4 and my old board - 6'4, 18"3/4, 2"1/2
This morning I gave it a try and I only struggled sooooo hard just to catch my first wave. I thought catching small waves on my 6'4 was already difficult, but this one is even more difficult! Normally I see a lot of surfers with short hybrid fish boards catching all the waves and even more easily, while I always have to paddle my 6'4 like there's a shark behind me just to get one. But now I have this hybrid and it's not as I thought
. I paddled so hard and waves just passed under me and I knew that if I was using my old board I would have caught all of them.
Do I need to catch waves a bit more late for the right timing? I know that with some length gone I can't paddle as fast as before, but I feel that this new board gives me the same or even more buoyancy (I can feel it when I duck dive) and at least I'm glad I don't sink. Do you have any tips for me? I'm ready to put more effort in paddling if that's what I need.
Thanks so much for reading!
Jak

I'm 5'9", 165lbs, 24 years old and still fit. I'm from Thailand, living in Australia where my local surf is below-average/average quality with 1-3ft height normally. I started to surf one year ago and nearly all the time I've been surfing my dear old 6'4 standard shortboard. I learned on this board so I'm very used to it. I surf at least 2.5-3 hours nearly everyday and I'd say I'm an intermediate. I like my board, though I feel that it's not agile enough for my local wave size. So, after researching and thinking about it for a while, yesterday I bought a new board. It's kind of a hybrid shortboard/fish and the length is... 5'10

Here is the picture.
My new board - 5'10, 19"3/8, 2"1/4 and my old board - 6'4, 18"3/4, 2"1/2
This morning I gave it a try and I only struggled sooooo hard just to catch my first wave. I thought catching small waves on my 6'4 was already difficult, but this one is even more difficult! Normally I see a lot of surfers with short hybrid fish boards catching all the waves and even more easily, while I always have to paddle my 6'4 like there's a shark behind me just to get one. But now I have this hybrid and it's not as I thought

Do I need to catch waves a bit more late for the right timing? I know that with some length gone I can't paddle as fast as before, but I feel that this new board gives me the same or even more buoyancy (I can feel it when I duck dive) and at least I'm glad I don't sink. Do you have any tips for me? I'm ready to put more effort in paddling if that's what I need.
Thanks so much for reading!

Jak