We started on good friday as this gave us several days of both me & DP dealing with it esp as I am 7 mo pregnant.
Day 1 was like yours. We went through 7 or 8 pairs of pants. Lots of sitting on potty for ages (once on getting her to stay there no problem but if nothing coming, wouldnt get off for up to half hour) then flood of wee 5 mins later. Did finally manage to do a wee in the potty at bedtime and was overjoyed as were we.
Day 2 she seemed to have grasped when doing it so only 1 poo accident as time to get to potty from starting but still several wee accidents as not getting to potty in time. Would shout "I'm weeing" so generally half in pants, half in potty.
Day 3 similar to day 2 but no poo accidents and smaller amount in pants then most in potty but then went to friends and had 3 accidents in 1 hours including a complete flood which she seemed unaware of when she turned on toy hoover (I think it was the frequency). DP was desparing & ready to give up as Gina Ford had said she should have got it by day 3. But then at bedtime she asked for potty & did big wee before bed so managed to convince DP to give it another day.
Day 4 something clicked - asking for potty, only one little accident of a bit of wee in pants but not enough to wet trousers getting to potty to do wee.
That was a week and a half ago and I can probably count on one hand the accidents. No accidents in buggy or car or shopping trolley. Have managed some trips to park and has let us know in time to get back to the buggy from the other side to get potty out. Not yet managed to move potty to bathroom during day. Still need to be in same room or at least next door but am proud of how she is doing as is only 2y 4mo but needed to try now so time to settle before new baby arrives or else I dont know when we would have been ready to try again.
Dont despair. Remember she is used to just being able to wee & poo wherever whenever. She needs time to learn the signals & feeling. If she is loving her big girl pants (mine is) and doesnt want to go back to nappies, give her a chance. She will also feel that sense of achievement when finally does it in the potty and you can dance round the room together. Good luck.