I'm so glad your family is supporting you in this difficult decision. And yes, it is very difficult, as working becomes such an important part of our identity.
It is exceedingly difficult to get through the process of filing for disability these days. Even just 10 years ago it was much easier. Now it's something like only 1 out of 3 who apply will get it on the first attempt, and the rest have to get an attorney and go through the appeals process. The GOOD news is that attorneys are restricted by law to only be able to take a small percentage of your first check as their fee (they'll start the process "for free").
At the risk of once again sounding like a 'know it all', here is what I know about the process: Do make sure to keep copies of everything you submit to the social security department. They have a way of "losing" paperwork, and if you've got copies, you can quickly replace them and keep the process on track. This is true for what your doctor submits too -- which means you need to get copies, and make copies of your medical records, and any forms he fills out on your behalf.
Make sure your doctor(s) knows you're going to apply for disability, and make sure he also supports your decision. If he is reluctant, it'll be more challenging for you to get the paperwork you need to get through the process.
Go to the social security website and find and down load the form there, and see what they're asking. If you know in advance (and before your appointment with them in person) you'll be better able to answer their questions calmly and completely.
An old trick a lawyer taught me years ago: listen carefully to the question (or read the question carefully) and answer only the question asked. We all tend to elaborate and expand, and you want to be careful to not do that. Be factual, but also think about your worst days, and answer the question using the "worst day" as your guide.
Make sure you answer every question, even if your answer is something like "I don't know". The bureaucracy hates blanks, and I know people whose applications have been denied simply because they didn't fill in the blanks. Weird, but true.
Keep on top of your doctor (or his staff). Make sure they get the paperwork they need (you may have to call the social security office yourself), and make sure they get it back to the social security office (again, you'll have to call them, and maybe stop in the office. Like most things, "the squeaky wheel gets the grease". If you're there, "bugging" them, they'll get the paperwork done and on it's way.)
Good luck to you and your family.
...I am not a doctor, nor health professional, and don't pretend to be one, here.....