Sometimes you can appeal a suspension if the reason was due to medical or other issues. Some schools have an appeal process for suspensions, others do not; check to see if yours does.

If it was depression that was the cause of your grades or something else and if you were seeing someone (doc(s)/therapist/counselor) who can document your depression or what you were going through, you may be able to appeal it to get it expunged from your record, and so you have no barriers to going back there or anywhere else. To support your claim, your grades you mentioned were improving, this can also help support your case and with your documentation as things were changing again, beginning to improve. This will be encouraging for them to reinstate your status and to revoke a suspension.

Every school is different but make sure about what you need to do to be able to return the next semester, even if you don't or can't appeal. I don't know if this will help with the circumstances you've described, but I wish you luck. I know it's not easy sitting out. Sending you the best of wishes!