Your OP describes exactly the situation that I found myself in at the beginning of this year, ~January. I had just started the "final reboot" on this huge comic I've been slowly developing since like... 2007-ish? Middle School all the way up through post-college. Anyways the problem was that I started drawing it in Decemeber and it was the end of January and I was only 8 pages in, and even as a action fantasy type series, I probably wasn't going to get to the first action sequence until like... now-ish.
Basically I realized both that my story was too large and poorly cobbled together (the resutls of 10 years worth of writing and reboots, but without the story even being done and full of ideas that middle school me thought were good) and just that pursuing a project like that as a first project would have been an awful idea. No need chaining myself down to somehting like that when I'm still learning/practicing, ya know?
So I decided to promptly halt that project and started writing my current one shot shortly thereafter in February. This story is a neat tidy 50-60 pages that i know I can finish :> and the good part wont/didn't take forever to get to. And my drawing speed (in terms of pages per week) has already improved significantly. And I'm just learning "how to comic" better. Wins all around.
I don't know yet whether I'll return to that previous series or not, but I'm not too concerned about it for the time being. Since that story's something of a passion project to me, I'd like to draw it some day, but hopefully with a bunch more comic making (and editing!) skills in my pocket xD In the mean time I'm pursuing some smaller projects! I'm planning on following my current one-shot with 1 or 2 shorter stories set in the same world upon completion, and I'm in the process of wirting a short-ish length series I'd like to tackle after those :> That'll be my first "lots of chapters" project, but hopefully not toooooo many, and I'm planning to have the whole thing written out before I start so I know exactly what I'm getting into!