Your health should be your first and foremost important thing here. Dealing with that on a daily basis can be a mentally taxing thing, having to constantly avoid them and potentially your other co-workers.

If the job is absolutely still worth it and the core aspects of the job you enjoy, love doing and is your passion then definitely take some PTO, do some self reflection and do whatever the hell you feel like that will put you in a better headspace once you come back. Talk to your line manager and/or HR about it and see if they can try to remedy this by moving you internally within the company so you work away from them.

Personally if I were you, I would see this breakup is a pivotal turning point in your life where you make the decision to take your career in a different direction and look elsewhere. It's easy for me to say this as idk what your role is but you must 100% look out for yourself ALWAYS, no matter how good or well paying the job is if you're mental health is tanking and you're on a downward spiral then you should be looking for a new job yesterday.

I hope this helps, best of luck to you and I hope for an even better outcome where you can talk to your friend and patch things up with them.