my friends first baby was 10 lb 3, due to undiagnosed GD...her second pregnancy it was diagnosed and controlled and her baby was just under 8 1bs.....!
i think that if it is GD again..but controlled well, there is no reason you should not deliver vaginally again....sounds like your labour went very qucikly once the syntocinon was administered...
do you know how long you were pushing for...?
you could do perineal massage this time...this helps prepare the perineum to stretch and gets you used to the ring of fire sensation!! will do a link for you
a water birth is a good idea if you can have one as does support you more and takes pressure of the perineum.....
also, a well controlled delivery with you breathing the head out , not pushing can help reduce trauma......
what position did you deliver in last time? all fours or over a birth ball can help reduce tearing by taking pressure off the perineum...
IMO ...being told you need a c.s at this stage is wrong.
if your consultant is very pro c.s , you can change consultant.