Hi. I can understand the pain and frustration you must be feeling. Anxiety, nightmares, irritability are all problems that can be treated. Since you are also having suicidal thoughts, it's important that you seek a Psychiatrist in your city and seek help without any further delay.
Next Steps
You must initiate treatment as soon as possible. Also talk to your parents and tell them about you having suicidal thoughts.
Health Tips
With proper medications and psychotherapy, you will feel much better.