Just from reading your request, I'll wager that you are a 'melancholy/phlegmatic', and your daughter is (at least partially) a 'choleric' (look them up. There's a lot of stuff about the temperaments online).
I challenge you to watch 3 episodes of Supernanny, and you'll see how to MAKE a kid stay in time-out without spanking or yelling. YOU must be in control (and that means in control of your OWN emotions, especially). When you 'lose it', everyone loses. You just have to make it happen.
My mom (now in heaven) gave me the best one-sentence parenting advice that I've ever come across. She raised 4 of us (I'm the youngest), and my husband and I have raised 4 and are helping a little with 3 grandkids. Here's the advice:
"Never say anything to a child unless you mean it." That means don't fuss, don't threaten, don't promise, don't yell, don't nag, don't plead, don't compromise, and don't concede! Say what you mean and mean what you say. Cause it to happen if it takes all day.
On the other hand, choose your battles. You don't make a big deal about perfectionistic stuff -- her socks (shirt, pants) being wrong side out, on backward, or not matching when she wants to 'do it herself'; but you DO have firm rules about not playing while they're eating, bedtime, etc (the 'biggies').
There's also the dynamic of 'love languages' (and you can look that up, too). There are 5:
Quality time
Physical touch
Acts of service
Words of affirmation
Receiving gifts.
It sounds as if your love language might be 'acts of service' (when someone helps you or does a chore for you, you feel loved), and hers sounds like it's 'quality time' or 'physical touch' or 'words of affirmation'. She just needs to 'be with you' and/or be cuddled, patted or touched in a loving way and/or have words of compliment or encouragement on a regular basis to feel loved (it wouldn't hurt to try all 5!)
2-3 yr olds is the most exasperating pre-school years, but if you don't get a handle on discipline now, you'll be hurting when she (they) reach ages 12-18. It's not about being mean or bossy. It's about knowing yourself and loving yourself.
You probably need to get completely away from your daughter for a couple hours once or twice a week. 24/7 with a (strong-willed) 2 yr. old and being pregnant is NOT healthy! Believe me!
Any further questions, message me on here. I'm rootin' for ya!
God bless, Merry Christmas, and happy parenting!