HELP!! I had my 4 month old kittens spayed

I had my 4 month old kitten spayed on Thursday. I haven't had a new kitty in
a while. We lost our cat of 10 years in Sept. Anyway I always thought that
6 months was the age to "fix" kittens. But they say you can do it earlier as
per 3 different vets. So I figured they knew what they were talking about.
Maybe 4 months is an okay age. They are my BABIES you know. Anyway I had
them spayed on Thursday morning. I adopted them from the pound and they use
their vet. Seemed like a great vet. Well Sugar came home with 7 STAPLES and
Mikey seemed to have no stitches, nothing, maybe glued together? Anyway it
is now Monday and they are SO lethargic but IF I put water and food in front
of them they eat and drink (a little). When I got home today I called the
vet and they didn't answer so I called 2 different emergency vets and they
both said this is NOT normal but if they are eating and drinking then maybe I
should just wait to see the vet tomorrow. I just feel TERRIBLE! I have a
siamese I am going to get fixed but I am afraid now. She is 5 months old.
OH PLEASE tell me this has happened to someone else. I am SOOOOOO worried.
Why are my babies suffering? I feel like a monster. I have 3 dogs all
spayed and they NEVER acted like this and my older cat whom passed never
acted in this manner. HELP!!!!!!!!!!
Amanda