D..
I'm not about to tell you that you should have a baby, E.. You sound almost desperate here, and to me that means you need to work on THAT part of your life, rather than bringing a baby in the mix. It almost sounds to me that you think that a baby will fix all your problems. That's not fair to the baby, and it's very far from the truth.
However, I do think that you need to have the IUD removed and let your uterus have some "time off". Use a diaphragm and work on getting your ducks in a row to lower your stress level and get your home lives in order. You need to be taking pregnancy vitamins, exercising, eating right, getting enough rest, and be HAPPY in your life. All of that will help your high-stress job be LESS stressful.
Go to the library and check out a Dave Ramsey book and use his principles to get your financial lives in a place that having a baby would not pulverize. Concentrate on being successful in getting this totally in order, organizing your life and enjoying your daughter. You'll be much clearer in your mind and your heart by the time you straighten out your finances. THEN you can consider putting the diaphragm aside and just enjoying your love making and your husband. It's SO much easier to conceive if you aren't trying so hard and dealing with so many stressors, like you are talking about.
You asked for advice. I hope you don't think I'm judging you. I'm not. I do think that you need to work on yourself before bringing a baby into the mix. It's so much harder to do all of this once you're pregnant. Do it now and do it with the knowledge that it's for the good of you and your family, whether you have another baby or not.