Is it just the way i think?

I feel sad everyday. I dont know why. Some told me it’s just in my mind. Sometimes i just wanted to cry for no reason. I keep on doubting myself. Theres a lot of what it. I dont know what is happening to me. Its been more than a year that i am feeling like this. Sometimes, ive been thinking of killing myself. I dont know. I think im losing my sanity already.