undermined by partner

[etti1978]

my husband works very long days, so i do the most of the parenting on my own. since christmas have noticed a huge shift, he seems to be getting more involved, but i am not sure if its in a good way. he seems very critical of me. more than he has ever been before.
my 6year old had tonsilitus 2 weeks ago, we went to the dr and he gave penicillin, but the day after she was so much better we never started the course. however 2 weeks later and its back with a vengeance, so my husband took her to the dr and got penicillin. however she is refusing to take it. i talked it through with her and explained it would help her feel better and reminded her of all the fun things we had planned which she needs to be better for.
he has completely undermined me and said she doesnt need to take it if she doesnt want to.
today has been awful. she's just played one against the other.
I said to him at lunchtime we need to be joined up. i need him to back me up.
and then this afternoon when i tried to give her the dose, she refused and ran to him. he sympathised with her and agreed mummy was being too harsh.
ahhhh i don't even know what to say to him. I've just put the kids to bed, have told my oldest we will try again tomorrow with medicine.
i feel so fed up.