OP, I was about to say that "toddlers" are the best bit about parenting - but then I saw that you have one already.
I had babies and toddlers together, and used to fantasise about a stay in hospital or prison, just to have a break and someone else to do the cooking.
That aside: you might perhaps find it a bit better if you make a few tweaks.
You shouldn't be anyone's slave 24/7. I was Mummy when mine were that age - but from 6AM - 6PM. After 6PM, they were in bed. Illness was the only reason not to be. I know it's not in line with various other ways of parenting, but I figured that they had my attention for 12 hours solid during the day, every single day of the week (playing, reading, talking, singing, etc, etc) - and the only way I could do a good job of those 12 hours was by having had enough sleep myself.
Sleep deprivation is horrendous, and it makes everything else seem insurmountable.
I would suggest you do some proper sleep training, which will be difficult and upsetting for both of you - but it does generally reap rewards.
I would also drop the breastfeeding. At 2.5, my DC were all eating more or less the same as us - just cut up a bit more, and in small portions.
Again, I realise this is not in line with the type of parenting you've been doing - but on the whole, if things are difficult with children, you have to look first as what you can change (sometimes it doesn't make any difference, as some children are just very hard work!)
My experience of children of that age is that they are absolutely hilarious, and are mini anarchists and visionaries. It was my favourite age.
I'm crap with teenagers, though.