That's why they call it "the terrible twos" and you're just about to hit it. Like the other person said, your daughter is testing her limits, and you're showing her where they are. So you've shown her that if she screams loud enough and long enough, she gets anything she wants. I know when you're about to lose your mind how much you want those few minutes of peace that you get when you give in, but if you do, it's going to be worse next time. We had an awful time getting our daughter out of our bed. We probably had three weeks when she stayed up all night screeching, and it was that bad because I gave in for so long and kept putting her back in the bed with me (I was just so tired and sleepy!). My son was happy in our bed or in his crib, so I thought it would just work that way again if I did the same things, but I was wrong.
If you stop giving in to her now, it's going to be bad for awhile, maybe really bad, but if you wait until she's older and used to getting her way, it's going to be much worse. It helped me when somebody told me, "all kids do this at some point. They have to figure out how things work, because they don't know. You have to show them how."
I'm a SAHM, too. Being on-call 24 hours a day is stressful. I didn't go anywhere or do anything for at least 3 years after I had my son, I felt like I just couldn't leave him, even with his dad, who is great and has more experience with babies than I do. Do you have a hubby or grandma who can watch your daughter for an hour or so? Even if it's just to get out and walk around a store or something, you come back feeling so much more able to deal with things.