1) what is your hourly rate and...
2) do you only have one child? Or several?
[edit]
Nevermind, I see that you have two kids now. Is the 8 year old eligible for free lunch? If so, s/he might also be eligible for state medicaid as secondary insurance.
I'm leaning towards sticking with the 22 hour a week, balanced & low stress method for a year or two, then reassess once your baby is out of diapers. And what you have presented here isn't really your only options; as a single, divorced working mother of a toddler. In many states, you're child would almost certainly qualify for WIC; and if s/he qualifies for WIC, s/he also qualifies for state medicaid (as secondary insurnace) for the toddler, but not for yourself. You might also qualify for state subsidized medical coverage if your wage rate is low enough. And $600 per month for high deductible insurance for one adult and one child sounds ridiculous to me anyway. If it were me, and I could get medicaid support for the kid, I might just let insurance ride for 2016 and pay the tax "fine". Particularly with $35K in the HSA. I would review my umbrella insurance coverage with my non-employer insurance agent, though. My umbrella insurance policy has a catastrophic hospitalization clause in it, but is not considered health insurance, so it doesn't have to comply with the ACA minimums and is way cheaper. Also, some employers have an obscure benefit for legal consultation services; that can often help you apply for state & federal aid.
In short, there is no reason that you can't take a couple years off from saving to enjoy life with your tot in the present.