Need help beefing up stamsorc.

I'm frustrated nearly to tears here. I've followed so much advice, I've had people build me armor, I've learned an entire rotation of new skills, and I still can't !@#$!#$@$ solo the Craglorn delves. I know it should not matter that they are group delves, I've SEEN people solo them and I get told all the time that a good enough player can solo anything and I'm !@#$#@!% *trying* but for fracks sake what the hell am I doing wrong??!

Here's what I've got. Mechanical acuity, 5 pieces. Kra'gh helmet, still don't have the shoulders, RNG hates me so I just have a stam shoulder placeholder. Nirnhoned dagger right, Infused left, mech acuity nirnhoned bow. Spriggan necklace, 2 rings of agility (robust).

Front bar I'm running deadly cloak, trap, blood craze, bloodthirst, hurricane, flawless dawnbreaker. Back bar crit surge, hurricane, poison injection, endless hail, bombard (caltrops is not happening, I will not go into Cyrodiil alone and there are never any zergs when I'm on), & ballista.

574 CP, have put it into all the areas I'm supposed to for stam sustain and damage reduction and all that good crap.

I'm at my wit's end here. I thought I was doing well when I started getting through public dungeons just fine but this mess with delves is getting me beside myself. Every time I do my best to L2P as people tell me I'm still never good enough. It's getting very depressing.