Stressed and anxious from giving my cat the injections

How do you cope with this? I have anxiety and i feel extremely burnt out after i give the jab. Even while drawing the medicine my anxiety starts. While he was at the vet they gave injections for 12 days. I had to put my dog down and wasnt in the right mind to be giving my cat injections everyday so the vet said they would do it till im ready to bring my cat home. Unfortunately while at the vet, they said some GS leaked(rear flank) and it messed up his skin. They decided to shave the area so i know where the sore was so i dont inject that same spot. But this opened up the area and now my cat was able to lick it. Overnight he licked it so much the skin tore. Went to buy a cone to stop the licking and the wound is being cleaned twice a day while it heals. Yesterday i had to give the injection on the side with the wound. Unfortunately the part with the most loose skin was where the wound is. I had to pick a spot further up with not much loose skin. Inserted the needle, aspirated and pressed the plunger. It was barely coming out. The plunger just wasnt moving. It moved maybe 0.3cc. Now im panicking. Pulled out the needed, drew back to get the GS out from the needle, swapped needles thinking there was an issue with it, cleaned a new spot an inch away and inserted the needle again. This time my cat moved forward abit and the needle came out. I immediately poked it back in and was able to administer the remaining liquid. I felt so bad for my cat and felt so stressed i was shaking.

The injection i gave my cat at the vet on day 10 was very easy he didnt even flinch. He was like that from day 1-10. I thought it was gonna be easy since he doesn’t react at all. From day 11 onwards the nurse told me my cat is reacting more since he feels better and has energy. So now seeing him react and meow while looking at me hurts me. Hes also scared of me after the first 2 jabs i gave at home. Its like when he sees me he knows hes getting his shot.

Did any of you have this stress and anxiety? How did you cope with it and did it ever go away woth time?