Usually when I do really complex or -- shall we say -- 'argumentative' projects, I'll have something like a 'Snap-Tite' or 'EZ Build' kit on the side, in parallel. (Those are usually mainly to use up a set of decals I've got collecting dust, not cool enough for a 'major' project, but too good to toss or ignore.)
Since basically any extra effort on an 'easy' kit is a noticeable improvement, that feeling of accomplishment goes a long way toward putting the frustration of the 'big' kit into perspective. It's like sitting back and taking a deep breath...and getting something positive done, at the same time.
It really helps.
[And...whatever you do...I would strongly advise against yielding to the impulse for a SHVIT ('spontaneous high-velocity impact test' -- i.e., hurling the dratted thing against a convenient wall, concrete floor, or other non-yielding surface.) It does feel sublime at the moment, I'll grant you -- been there, done that -- but I personally have never not regretted giving into that frustration, afterward. When you do complete a project like that, it's doubly satisfying to look at it and think, "You have no idea how close you came...."]