Help me put into perspective my change of income with almost $1million invested

My longtime job is restructuring and changing my compensation from salaried to 100% commission which I'm hopeful will result in me making more money than before. They're no longer paying for my health insurance. My spouse cannot work and brings in no income. I'm trying to calm my nerves while I wait for the new compensation structure to shake out. Here are my stats:

53 years old

$940k invested

House worth about 1 million but no plans to move

$200k+ mortgage

High cost of living area

Health insurance through the health care exchange costing me about the same amount I was contributing on my employer's plan.

One child to put through college in about 6 years. Have saved roughly 25% of what I will need for that.

I also expect to inherit a substantial sum of money from older relatives at some point in the not too distant future but obviously not banking on it.

I have about 8 months of living expense in cash but after that, if I'm not making enough commissions, will be borrowing against my investments at about 7% from a personal credit line amounting to around $250k.

Help me sleep at night - this is a good financial position to be in to take on a career risk, right?