Gotta second the meditation suggestion. Also, exercise. Even if it sucks. Definitely alcohol and benzos will do nothing good for you, if you're not physically dependent really try to avoid that.
Obviously our experiences are not equivalent I'm sure but in my experience the intermediate step is just to get yourself to a place where you can make a kind of uncomfortable peace with the uncomfortable thoughts, such that you can accept that they're something you're experiencing and that, yes, they are very unpleasant and yes, in the short term some kind of downer would no doubt suppress them... but despite all this they're not representative of reality and you really just have to try to face them, and then start to ignore them, and do the healthy stuff you know you need to look after yourself even though you really don't want to and the thoughts might be telling you why even bother or whatever.
After a while of doing this they will start to lose their power and ultimately quieten down in most people... but just suppressing them or blocking them out with distraction will usually just serve to amplify them in the long term. Meditation is the best way to really start to face them even though obviously it can be really unpleasant at the beginning.
