It sounds like you've been having a really stressful time lately & as you pointed out, that's probably a big reason that your self harm has gotten worse.
Self harm can sometimes have the effect that it makes you feel calmer temporarily - do you have anything else which you could use to self-soothe in this way? Sometimes doing little pampering things like having a nice bubble bath or watching a movie you love could calm you down as well. Have you got any of your own distractions which help you when you feel like self harming?
If you managed to minimise your self harm to every few weeks or months, then you can get there again - I'm sure you will once your stress level goes down.
Would you like to talk about the problems you've had at work? Work can be difficult enough when you have mental health difficulties, but when you have trouble with colleagues too, it can feel somewhat unbearable. Do you have anyone you can talk to in 'real life' about what's been going on for you? Maybe a friend, family member or some professional support?
It sounds like you could do with some support in managing the anxiety which triggers the feelings which lead to your self harm - do you have any tricks which might have helped in the past which you could re-visit?
Also, you're not a failure at all, we all struggle in our own ways & it sounds like you're doing the best you can to try to manage.
Look after yourself.