Take the time you need to step away from aspects of your life that feel draining. You may not be able to take leave from a job or certain responsibilities, but temporarily leave other activities that cause unnecessary feelings of obligation. For example, if you are on a committee, see if someone can take your place for a while.
Surround yourself with supportive people. This doesn't mean you have to permanently cut ties with anyone, but do take some time away from acquaintances who are not fully supportive of you.
Begin an exercise program---such as a martial arts class---if you are physically able. You do not have to choose anything particularly strenuous; the purpose of this exercise is not to lose weight or look great, but to get in touch with your body in a positive way.
Seek a good therapist when you are ready. She will help you discover how to feel good about yourself again. Avoid any who make you feel shame or guilt about your situation. Choose a therapist who understands abuse and that abuse victims are not weak people. Do not allow anyone to shift blame to you.
Stay away from the abuser and anyone whose actions or behavior resembles his. Initially after you have left the abusive situation, you will be more vulnerable to falling back into your old mindset and feeling weak.
Pursue something---big or small---that you really enjoy and feel you are good at.