Cutting is not a symptom. Its a way to deal with pain and a consequence of feeling bad. I SI for several years and it was a maladaptive behavior I picked up because I didnt know how to deal with the pain I was experiencing. A symptom is the depression youd be feeling.

Your mood is probably unstable because your mom is being sour. Anybody in that situation would feel out of control. Moods can be unpredictable at times especially when under a lot of stress. I think you should keep writing and try to find a solution to deal with your mom. If mood continues to be totally unstable then its a good idea to see a t at the very least.