If Tulex is right then you'd only gain an extra few gear inches going from a 34T to a 30T. To switch you may need some or all of the following components - cranks, left shifter, long cage rear derailleur, front derailleur. You could still go some way with a MTB cassette (>30T) and a long cage rear derailleur that would be cheaper than the triple switch.

I would definitely give yourself time with your current set up though. Choose a tough, but not impossible climb and plan to conquer it. Get to know it well, pace yourself and set incremental goals that make sense (not stopping, increasing cadence, climbing at a higher speed, or bigger gear etc). It takes time to get used to riding hills, but you can improve.