I know, it seems like you'll be knitting this thing forever! I am a SLOW knitter and I often feel that way! LOL-but just think, when you're done with this part, you won't have to then go and cast on for the BACK (or front) and you won't have to seam up those pesky sides!
I like to change patterns a lot, usually, too and knit in the round instead of in pieces, and just the fact that I am winging it makes me nervous, and contributes greatly to my feeling of 'this is never gonna end!"
When I feel this way I usually start a new, and SIMPLE, project that I know I can finish quickly and get some relief from the project that goes on and on. I usually feel much better after that and can work on the pain in the neck item happily for awhile
Hope that helps!
BTW, I just recently finished a couple of projects that took me over a year to complete-so you're pretty darn fast, actually! LOL