Coping with 5 neurodiverse children with adhd and ptsd myself

Hi mums. I would love some advice on how to cope and/or how to help my teenagers to understand.
I have three teens - two of them adhd (one possibly BPD) and the third being assessed for ASD. I also have two younger children who are ASD and ADHD - so life is very full on!! I have ADHD and PTSD.
Most of that is managed, all support services are in place. But to be honest, the biggest day to day challenges I face - is all teenagers and their social lives, constantly asking me to drive them everywhere, constantly wanting friends over, parties, boyfriends, shopping etc. I am legit their taxi. Yes, I frequently say no - met by “why?”. I sometimes respond with “I don’t have to explain myself to you, I’m the parent”. Sometimes I do explain. But no matter how reasonable and flexible or firm and strict I am with them - they just take, take, take.
I know to a degree this is normal teenage behaviour. But I don’t remember the last weekend I had with my husband at home with just our family. It is utterly exhausting and we both feel this! How can I help our teenagers to see this from our perspective?
At times they do take on their independence and walk or train themselves, but for every one time they do that - they expect us to drive them the other 10 times and then they argue “but we do walk sometimes” - and they think that’s enough. They’re so mentally exhausting.
They do help around the house too sometimes so they’re not bad teenagers at all - it’s just their social life is so draining on us!!! Any advice welcome please! From two very drained neurodiverse parents!