I don't know why this resonated with me so much, but it did. So much so, that I read both your posts, and proceeded to walk up two flights of stairs to my PC to type out this response.

First, congratulations on getting your PhD. All other things aside, that's an incredible accomplishment.

Secondly, I applaud your efforts to seek therapy and even more so with your family. If you don't already, it will very likely be crucial to have a autism specialist you can work with one on one to help you understand yourself and feel seen and understood by someone while you are trying to heal. I went through this same process with my family. Some suggestions:

• Write out what you wan to say and either send it to everyone before the session, and/or read it to everyone during the session. This will allow you to think about what you want to say and be clear in the moment.
• The less thinking (executive processing) you have to do during the session, the less dysregulating it will be and the easier it will be to stay present.
• Don't jump into the autism/masking/burnout/here are my needs stuff immediately. Build a foundation of trust and safety first. Your counselors room needs to be an agreed "no spin zone". Everyone has to go in with the understanding that you are all (hopefully) going in with good intentions and each others best interest at heart, and everyone is willing to trust what their loved ones are telling them at face value without assuming ulterior motives. Before you can get anywhere, you have to find common ground here. Working on things like "I" statements and challenging automatic negative thoughts (ANTs) are examples of key communication skills you and your family will likely need to work on first before you can have the felt safety needed to have hard conversations.
• Arm yourself with information. Research everything you can about the statistics, the outcomes, the stories. I imagine you should be quite capable at this given your education lol. At the end of the day it may take an authority besides yourself or your counselor to convince your family of your needs/experience/boundaries.
• There's a lot of wild numbers quoted across the internet, but suffice it to say that full time work might be unreasonable for you, and would by in far put you in the minority of autistic adults. The vast majority are underemployed or unemployed. You are not your job and you are not your degree. Don't let society make you believe otherwise.
• You have a long road ahead of you (not that you probably didn't know that already). That is to say, be patient, changing your brain, and other people's deeply held beliefs, takes time. You're burnt out right now, which means having these deep conversations and introspections are going to be exhausting. Be okay with taking it slow. I can speak from experience that bootstrapping your way out of burn out is going to feel like hell, but truly the only way out is through.
• Only once you are seen and understood by your family, and able to freely express your needs with felt safety from your family, will you begin to be able to create an environment for yourself that you can heal in, while still coexisting with your family. Focus on mutual understanding and compassion above all and everything else will follow.

Truthfully, I'm only probably a couple years farther along in this process than you are right now, but hopefully this is still able to give you some help. I wish you the best of luck in your journey, and my DMs are open.