Make a fate party, put it in Party Finder, say "Anything welcome, atma/alex/light/exp" there are tons of people who fate farm and then you won't ever die. Farm at the fates of your level, you can look up each zone and see what level fates pop in it. Also there's tons of exp bonus stuff you can also use, like the FC action or GC thing or food.

Also when you do queue up for dungeons as DPS, click the "in progress" button, you may get lucky and get into one already started. I usually keep on my queue and go do other stuff while I wait (craft/gather/whatever/irl stuff too).

If you're in an FC use your healer and tank friends to get you instant queues. If you're not in an FC, maybe look into it, it'll help you a lot with your problem.