[A] Life is a struggle, will always be a struggle. That depresses me and makes me feel hopeless.
if I am stuck in [A], I must be immature and a bad person.
The way out:
Take the word "always" out of "life is always a struggle", actions taken now pretty much mainly affect the near-term, so "always" is probably not helpful.
Instead of considering an entire "life", just focus on the particular situation under consideration, and just in the near-term.
Instead of using the word "struggle", use the word "challenge"
So if planning a trip is building anxiety in me, and, because of building anxiety, I end up thinking "life is always a struggle", break down the planning for a trip into the single task to consider right now, like the act of packing for a trip, and then say "packing for a trip is a challenge - lets use a simple strategy, available now, for tackling that challenge"
So we went from [1] "life is always a struggle" to [2] "packing for a trip is a challenge - lets use a simple strategy, available now, for tackling that challenge"
And this is good!

What changed here was "attitude" and "perspective". "Attitude" and "perspective" are available to be changed quickly, on demand, to great benefit.