Ganbatte - Don't give up :)
I had 0 issues with Stone Vigil as healer, did not wipe once yet
And I was quite surprised because Cutter's Cry was a hot mess (oh so many wipe that I though I was a terrible terrible healer)
Don't think you are a bad healer, at worst you just need to practice more and keep your skills and equipment updated
It is also hard to find great synergy sometimes in DF
the succeed/wipe is sometimes out of your hand but Tank and Healer are the one who will always get accused first
here is the pattern:- Tank blame the Healer
- Healer blame the Tank
- DPS blame Healer and/or Tank
Don't worry too much, do your best and keep trying
If you have good LS/FC, ask for some help as well ^^