How risky is a voluntary 90 day sabbatical realistically?

The reason for this is pretty simple, I'm noticing I've started to burn out and just simply stopped caring about my job. Part of that is my fault as I'm likely not taking care of myself as well as I should (among other things, such as a medical issue that spanned the majority of the past 12 months resulting in a lack of regular sleep for weeks at a time). Part of that is the environment I'm in (the undesirable portions of my job are becoming more and more frequent of an event, largely because I've been forced to abandon things I consider basic essentials...like git...because certain people simply refuse to use version control in 2016. I wish I was joking. I'm not.).

One of my friends has noticed in the past ~12 months I've had more and more trouble controlling my temper which is also just not the sort of person I'd like to be.

It is also possible I'm overreacting to my lack of motivation, the trouble I've been having maintaining a stable sleep schedule, and being forced to deal with stuff about my job I loathe more frequently.

I could simply tough it out, continue to have shit productivity, and probably last another 3-6 months before I burn out completely.

Money wouldn't be an immediate issue, I've got enough to last me ~18 months without touching retirement accounts so I'd probably have a decent chance at getting a decent job (honestly, a low stress job making $50k in a LCOL location is all I require which for any kind of software development should be relatively trivial to get [although convincing an employer I would stay given might be impossible with my experience/salary history]).

Thoughts?