Not true. SSDI may take a while to get...some folks fight for years...but in your case, it should be a slam-dunk. Once they approve you, you get your first payment almost immediately. I think for me, it took about 4 months, but we moved from one state to another, and several things had to be restarted. (Different states applications get processed in different places.) They sent me to a doctor for evaluation, the local SS office notified me after about a month and told me I had been approved and in what date I would get my first check. If you're approved, you get paid from the date of application...or as far as 18 months back if you've been disabled and unable to work that long. (I got a nice fat check to cover 18 months.) If you haven't reached full Medicare age, your Medicare kicks in (a) when you do hit your full Medicare age, or (b) 24 months on disability.
This page provide general information about Medicare.
www.ssa.gov
You definitely want to sign up for "Part B" at the same time you sign up for Part A. Not doing so can cause delays in coverage and trigger a higher cost to you in monthly premiums.
Medicare is our country's health insurance program for people age 65 or older. You may also qualify if you have permanent kidney failure or receive Disability benefits.
www.ssa.gov
you should have already signed up for Medicare. You should do that 3 months before your 65th birthday.