This is one of the most frequently asked questions of any OB/GYN. The answer is that each person is an individual and the time that it takes to get back to what you feel was your pre-pregnant state will vary.
Exercise is a good way to start to build back your prior cardiovascular condition, however, you should consult your physician before beginning any exercise programs.
Dryness in your hair and hair-loss is a very common concern and a common problem in pregnant and nursing women. While you are nursing, your estrogen levels are very low due to the high hormones required to nurse, and this causes hair loss and brittleness. When you finish nursing, you should experience a tremendous improvement in this condition. However, this can take from several weeks to several months depending on the individual.