Jon-I retired last year. What I'm about to write, you probably already know, so forgive me if I'm wasting your time.
First, ya gotta go to a transition assistance program class. I went about two years before I got serious about retiring, and then again when I made the decision to retire. Lots of info, especially about retirement and disability benefits.
If you haven't done so already, go see the doctor about ANYTHING. You need to get it in your records NOW rather than try to get a determination of "service-related" later.
Talk to DAV or VFW about helping you with your disability assessment/claim. You don't have to go it alone, and you shouldn't. A retired Marine helped me with my stuff, and I got a pretty decent result out of it.
Disability rating math is WEIRD. If you need help figuring it out, holler.
They'll probably recommend that you transfer your SGLI to VGLI. Your choice; but look at the pay tables carefully. For me, I compared VGLI to Term Life over a 25-year period; VGLI was going to cost me about $900/month for years 23-25.
Consider Survivor Benefit Plan. It gets deducted before taxes, meaning that your retirement check is taxed a little less. And you stop paying on it around age 77 or when you die; and your spouse or other beneficiary receives a monthly check upon your passing. Couple that with a life insurance policy, and you've made sure that your spouse can pay off any debts and take care of the bills.
Consider Tricare for medical insurance. Be aware that they just enacted a law that says if we're not within 50 miles of a military treatment facility, we can't get Tricare Prime. BTW: while you can use VA for your medical, you can't use them for dental, so you'll need to look for dental insurance. And your family can't use VA for medical, so you'll need to consider Tricare or something else for them.
Praying for you.