If by some ill chance you should have to apply for SSDI, be aware
a) the rejection rate on first application is extremely high – I’ve heard 70%. Second applications are much more likely to be awarded. If the second application is rejected, then might be the time to hire a lawyer.
b) No matter when you apply, your payment is based on the time you became eligible (six months after disablement IIRC). When the award is made you’ll receive a lump sum to make up the difference.
c) Don’t fall into the trap of their online application. Find an office, make an appointment, and apply in person. The person interviewing you will know the stuff inside out and will save you much time and skull-sweat. You can walk in at the office, but an appointment may save you a lot of waiting room time.