Antidepressants doesn't contain any steroids in them, so no need to worry about that aspect. They do have side effects like any other medicines, but nothing serious. Once you get well and stop taking the medicines, the side effects will subside. How long do you need to take medicines, that depends on the patient profile and your disease severity, and the progress you are making.
Next Steps
Regular follow up with your treating Dr and take advice regarding these issues.