Non-sugar cat, dental... help?

Hi,

My 2nd cat, a neutered male named Mao, got diagnosed Saturday night at our local ER clinic with elevated kidney levels (he got sub Q there and sent home with), elevated WBC and SEVERE dental disease.

His blood work otherwise is beautiful but I need to give sub Q, which I did for his sister Fena which was nerve racking - he doesn't wanna stay still like she did? But they gave me 1ml Clavamox drops and bupe pain reliever 2x daily which he takes SOOOO much better than Fena ever did.

But he still won't try and eat wet food... maybe 1/8th, licking the liquid? But Dr. Elsey's and YoungAgain kibble he devours...

I can give his meds, he wants burrito wrapped and tucked into my side.

But the sub-Q... I need help? Fena lays in my lap and gets it, Mao freaks out!

I've tried holding him like for his oral meds but he "knows" and freaks...

I feel like I'm missing something or doing something wrong, but I can't remember what?

It's so crazy! Fena hates oral meds, but likes needle-ones. Mao likes oral meds but hates needle ones.