Cognitive behaviour therapy is evidence based, and short. A course of treatment takes about one hour per week for about 12 weeks.
It's effective for about 60% of the people who go through it.
Mindfulness and meditation are useful tools that give you a structured way to examine your thoughts.
Medication is useful for many people, but you may need to try a couple to get one that suits you and that works.
If you're having thoughts of suicide you should carefully seek medical help. If you have a plan you need urgent medical attention.