Op there is some great advice here,
I think it may help if you,
Fake it till you make it, forget about whether or not you like her at the moment, disconnect a little, lower your expectations.
( l had 2 under 2 and my DH was often away, l took turns liking and disliking mine as they went through different stages! ) But l learnt to walk away and hide my frustration, keep an emergency bar of chocolate and a magazine in the loo and sit in there and take 10 mins when you think you may snap!
Set non acceptable actions and consequences and put on a kitchen poster, go through them with her calmly.
Ie for hitting each time a favourite toy gets removed for a day (put in box in garage or loft)
For going a week without hitting a favourite activity is done on Saturday, ie extra park/playdate/swimming . Mark each day towards this goal.
Just start with two actions you want to work on to begin with, add more once you are making progress.
Plan well ahead for potentially difficult situations, each day before you start. What can you do to mitigate problems.
eg, If l had to go somewhere where mine would get bored after a short time and it would be difficult to leave, l would bring a small new toy each (often charity shop items). Once they got fidgetty l would give toy/colouring book etc.
Commit to going grey rock in the face of bad behaviour, no shouting or arguing back, but always know what consequences you are going to use and make sure you are actually able to do them in the situation you are in. Plan.
Choose a course of action and don't change it, be very consistant.
If it is financially feasable, get two half days off with a babysitter, and do an activity you enjoy. When you feel you are going to yell, think hard about your next time off, for 10 seconds, it will calm you. Then carry out consequences.
These are things l learnt and may hopefully be of some help....