Go for medication with therapy asap. For that you need to go to a clinical psychologist or a counseling psychologist and a psychiatrist.
Try yoga meditation with this. And when you're getting irrational thoughts ask yourself what, why and believe in second chances. Hear affirmations by Louise Hay found on YouTube easily.
Next Steps
Go to a psychiatrist AND a clinical or a counseling psychologist. you require therapy with medication.
Health Tips
try yoga meditation as well, to help you with the process.