What do I do if Ashtanga Primary is impossible?

The Question

Hi all, I am trying to gain flexibility and mobility after finding out a lot of my issues with things like shoulder are due to having poor mobility. I wanted to try getting into Yoga. However, I have very poor mobility at the moment, ie can't even get close to touching toes. This means I am very far off being able to do most of the exercises in the Ashtanga Primary Series. Is there an alternative, easier, start which allow me to build up to it? Or, how would someone go about altering all of the exercises to an easier for to build up from? I am also doing this on my own, due to limited funds (I am being made redundant) / not being the most social person. I have adhd, so am planning on using this as a way to approach mindfulness as the typical approaches don't work with my mind. I figure giving me something physical to focus on might help externalise the hyperactivity of my brain and make mindfulness approachable. Any advice is helpful, but please consider my barriers (funds, adhd, antisocial, poor mobility). Thanks! 🙂 Edit: Thanks for all the great advice! Managed to do a full primary series after altering it to my level of flexibility. It was exhausting and I think it took me like 2 hours. People do this every day?? I definitely felt a good stretch in all the right places, but have a lot of work to do to gain flexibility.

— via r/ashtanga