Sounds like you need a healthy dose of anti-psychotics to blunt those suicidal/self-harm thoughts.

Probably need a hug as well.

*Internet Hugs*

It's going to be okay, just breath. In through the nose, out through the mouth.

Alternatively, if you feel like you deserve pain in some fashion, you could always try doing what I used to do (which helped a ton) and take freezing cold showers. I used to jump in the shower when it was warm, meditate and breath for about 5 minutes while sitting cross-legged in the tub, then when I felt prepared I'd stand up, breath, and slam it all the way to the coldest temperature I could get.

It has this intensely gratifying effect on the mind. Completely snaps you back to reality, and after awhile (I was doing this every day for 3 years) it starts to feel really good and calming.

I'd just stand there in the cold, turning clockwise to make sure I didn't miss a spot, and after putting my head under the water and taking in and letting out a couple deep quick breaths in order to manage the shock, I would sit down cross-legged again, and meditate while breathing in the cold water.

Talking about it actually makes me want to go and have one right now, haha.
You should give it a try.