Due to circumstance out of our control, I am FF my 5 week old DS -- since he was 10 days old.

We started on S26 as that is what the hospital gave us, but there was so much fussing etc (and as this is our second son, having BF first for 2 years, we were/are very unconfident with formulas)

We were adviced by MCHN to try Nan HA which we did. I have found that he still is very fussy at the bottle and throws up A LOT and had a lot of burping and gulping at the teat (I use Y teats). He would be incredible unsettled at 4am-630am (!!) but also from 4pm -630pm!

At my last visit (yesterday) to the MCHN she again suggested another change this time to Karicare De Lac. It has not yet been 24 hours, but he still is throwing up heaps and rather than burping is very very windy ...

What to do? Should I stay on the Karicare? Or go back? Is this normal?
BTW my pead didn't think it was ness lactose intolerance and he said prob this would just right itself in 3 months (I told the MCHN this and she said that she thought it would be worth trying the De Lac anyway and that is what she would di in my situation). Am I being neurotic then?

My DH thinks that DS hates the Karicare -- but it's been less than 24 hours so I am hesitant to say that. We also swapped formulas without doing any progressive or gradual change -- is that bad?

HELP!
Thanks!