question: do I need to see a doctor?I often feel really low and depressed , im angry and irritated by small things. I often feel sucidial and that theres nothing to live for. but after a few weeks or sometimes days I no longer feel like this. sometimes my head is filled with thoughts and I feel like my head will explode if I dont stop thinking and then I just get a headache. im 18 , female. I just want to know if this is anything I should show a psychiatrist?