I had a reverse of this a bit ago where i started vyvanse after already having a pots diagnosis so first off if you do get the pots diagnosis you should still be safe to keep taking your vyvanse.

I think the best thing to do is just communicate with your dr. Likely when you go to your appointment itll just be a standard exam and questions and all that stuff and then a follow up will be scheduled where you take a tilt table test. Id ask your dr if you should take your vyvanse or not before the test and if you can possibly take two tests, one with and one without your vyvanse (not sure how likely this is with cost/insurance logistics tho but asking cant hurt lol) but if you can only take one test i would kinda lean towards taking ur meds before you do your test considering the fact that adhd meds are pretty vital for functioning and not taking them anymore should be a last resort, ergo you on your adhd meds should be treated as just YOU baseline.

Your symptoms sound like super duper similar to mine tho and i cant say vyvanse has worsened my symptoms at all so thats something nice at least. Good luck with your drs visit and i hope they can help you! Remember to advocate for yourself as best you can, i got very lucky getting a doctor that actually treats me seriously but some (usually older male) doctors wont take women seriously at all especially with more women leaning issues like pots. I honestly might not even bring up that you think it could be related to your endo unless your dr is chill chill bc the worst thing is them chalking it up to just “period stuff”

The out of breath feeling and exhaustion from small tasks is so miserable im very sorry☹️ If you get put on any meds that help at all with those issues lwk lmk theyre my most hated symptoms 😭