Mount Washington is one of the hardest climbs in America if the OP references New Hampshire. It is an extreme example but it sounds like he lives in an area with very steep climbs. Keeping knee pressure down means keeping cadence up. Moving from a 28 to a 30 probably isn't enough.
My opinion -- get a mountain cassette / RD to start with the biggest cog you can find -- 12 to 36, for example. If 34/36 is still not enough, then change the crankset / FD / shifter for a triple with as small a granny as you can find. Your bike shop should be able to guide you to compatible parts.
Ignore the imaginary ties between climbing skill and gear ratios that some people believe in. The physics are all that matter.