in a lot of minds, comic artists are illustrators - in fact, the overlap is massive, and lots of illustrated books are just comics by another name.
but there are other jobs in the narrative arts besides illustrating books and making comics - theres concept artists, character designers, storyboard artists (although really, thats comics getting ready to not be comics). you can do all those things and still be an illustrator and/or make comics, as well. and you can write a comic in collaboration with an artist, or work by your own deadlines... theres no strict rules that say comics have to be what you dont like about them.
also, 63 pages in two months is a bloody good rate - you notice most webcomics get out maybe half that? even if youre doing this full time, thats just over 30 pages a month, which is the size of your average print issue - you're doing fine! and if youre doing comics on the side, then youre doing more than fine.
speed is an important part of serialised comics - but you dont have to make serialised comics. you can make graphic novels, you can make things that come out at a snails pace, you can make things that wont come out until theyre all 100% done. the serialised comic industry is a big branch, but only a branch of the comic industry, and theres plenty of other ways of working.