This response is provided based on the information you shared and should not be used as the sole source for making a decision. You should seek guidance from the chain of command, IG, JAG or other certified agencies before making any decisions. How you chose to use this information is totally up to you and is your sole responsibility.
Based on what you have described it might be excessive and you always have the right to appeal the punishment.
If you believe it is unfair, I would encourage you to appeal.
Make sure you are well prepared. Consider writing a statement, and request to appear in person. Be professional, factual, unemotional, and calm.Hope this helps to some degree.