I've dealt with this by pruning my Projects list down to things I expect to accomplish--or at least make major progress on--this week. For me, that means a maximum of about 7 Projects. Everything else goes on Someday/Maybe, knowing I may add much of it back on next week.
Does that help?
I always resisted the idea of putting projects that I can't do right now on Someday/Maybe. It seemed too much like pushing them into the far future, so I would keep them active. Lately I have tried creating a new list called On Hold. I feel less resistance to moving a project there (and also off my NA lists) as I know it will not get lost inside my more futuristic Someday/Maybe list. It also gives me a quick metric on my level of overwhelm; the longer the On Hold list the more overwhelmed I am and it is time to renegotiate some projects.