Struggling with Diabetes Management and Mental Health

hello everyone, I go by kitten I have diabetes t2 I have been trying to keep it in normal range but it's like a roller coaster. 300 then drops to like 52.what are some foods that will help to stop this happening. I'm in my 30s. I also have mental health issues. I like being a loner. I just feel like no one understands what it's like being miserable from mental health, I have low self esteem. my bf tries to make me feel better about my self.