You are either pushing to hard (into to many wings, to early) or are missing something vital (like the titan upgrades.) I've done full + masks on a few characters, and you should not be full clearing if you aren't super confident before you get Elite Extermination.

Remember, you only have to do the boss until Rank 6, then only technically 1 wing + boss (though its obviously faster to do more.) Even more importantly - you don't technically need to do a Lost zone until rank 12 iirc. So even less stress if you just wanna take it slow and steady.

By the time you have a rank 11+ cloak, you should be able to full clear fairly easily potentially even with orbs to spare. I'd maybe check a video out of someone running it on your class, it helps a lot. IMO, Rank 11+ and Gift of the Titans is when you can start doing mask runs even.

But yeah... its as stressful as you make it. If you want to get to Rank 15 as fast as possible, doing every single wing you can all the way up, its gonna be a trial by fire, and it will suck ass.