Everyone has great ideas already. This is what helped me...
(Found on a greeting card, and I edited it a little bit for myself.)
"Be there. Say "yes" as often as possible. Let them bang on pots and pans. If they're crabby, put them in water. If they're unlovable- love yourself. If they're not nice -YOU be nicer. Realize how important it is to be a child... Invent pleasures together. Remember how really small they are. Surprise them. Say "no" when necessary... Search out the positive. Keep the gleam in your eye. Encourage silly... Stop yelling. Express your love- A LOT. Speak kindly... Handle with caring. CHILDREN ARE MIRACULOUS!"
From 'Tao of Motherhood" by Vimala McClure:
"Pay attention and stay centered. You carry the mantle of 'Mother', the external principle of balance and stability. When your children's energy is scattered, be grounded. When your children throw tantrums, be still. Know what you stand for. Be firm and consistent to teach your children about boundaries. Thus you will root them in health, and release their souls to limitless."
I have these on my refigerator so I can read them if I ever feel frazzled. Stop. Breathe. And keep on truckin'.
You can't control her. You can only control how you react to her.
Don't buy junk food. Keep plenty of fruits out on the counter (in her sight) for snacks, and keep offering the veggies at every meal. She'll eat them. My kiddos loved dipping sauces at that age- it's messy, and fun, and a good way to get veggies and fruits into them. Apples or celery in nut butters, carrots in salad dressing, strawberries in yogurt or chocolate, veggies or pita chips in hummus, etc. Finger foods where they can use their hands make mealtime more like playtime. If you are a good influence with what you eat, that helps too. Also, meals don't have to look "typical" on a child's plate. We have a huge family and everyone prefers different stuff. Load up on the stuff they like and don't force the stuff they don't.
Pretend someone's watching you. I know it sounds stupid, but it really helped me a lot. I had to put on my "fake" smile and use my preschool teacher-y voice with my kiddos when they were on my last nerve. It works! They really respond differently when I change *my* attitude.
Get outside, and into the sunshine. We might not be getting bored staying close to home every day, but the children will. Even if you get out of the house for an hour, it really helps to break up the monotany of the day. There are lots of things you can do for free- explore your own yard, take a walk, go to the park, go to a lake or river and feed the ducks, go to a pet store and pet the animals, walk around the mall if it's too hot outside, go to a friend's house, etc.
Try to get at least an hour every few days completely to yourself. Whether it's taking a bath in private (what's that?), doing the grocery shopping, gardening, whatever. I really need some quiet time when I can just *be*. Some people don't need that time at all, but I really do feel "recharged" when I can get away, if even for a little while. When I come back I feel refreshed and ready to start anew. My soul needs some tending from time to time, and then I feel stronger and ready to "take on" my challenges.
As someone who has struggled with depression and the demands of being a SAHM to small children, I would suggest making sure you take care of yourself.
Your daughter needs you to be healthy, and to have energy. I take multivitamins and Omega 3s, as well as eating (mostly) right, and moving around. It was hard to take that first step and get off the couch and MOVE, but I felt so much better for it, and my kids responded so positively I couldn't help but want to continue improving myself and our relationships. I really was amazed at how positively they responded to my changes. (They still do!)
s Hang in there! Toddlers who feel secure enough to assert their independence are doing so because they know they are in an environment full of unconditional love. So, in some ways, tantrums and disobeying are good things! Try not to look back on what she "did" yesterday, or even earlier this morning, to upset you. Move on and try to make every interaction a learning experience for both of you. And remember that you're not the only parent who said "I'm never going to..." or "My kids will always..." Things change! We live, learn, adapt, and go from there.