More detail
Find which demand is causing the difficulty
Predictability and following through are different needs
You may prefer a dependable routine but find that ADHD repeatedly disrupts it. Making the routine stricter will not necessarily fix forgetting or getting stuck between steps.
Keep the essential order simple. For example, a leaving-home list can stay the same even if the time you leave changes. Put the relevant items beside the list so you do not have to remember where to find them.
Change the setting as well as the instructions
If a group is difficult, identify the part that costs you most: background noise, several people talking, an unexpected change or losing track of the topic. You may have more than one barrier.
Tell the organiser what would help: the agenda beforehand, a seat away from noise, a pause between topics, or permission to take a break. You do not have to choose whether the difficulty belongs to autism or ADHD before explaining what you need.
Make therapy easier to process
Ask your therapist to use a real example from your life rather than an abstract explanation. If you are still working out one point when the discussion moves on, ask to finish that point first.
A written summary helps only if you can use it. Ask for the agreed action to be separated from the background reading. Rehearse it together if you are unsure how it fits outside the session.
Notice what has improved and what has not
ADHD treatment may help you keep track of a conversation while a noisy room remains exhausting. That remaining difficulty may need a quieter setting, not more effort or an assumption that treatment has failed.
At review, give separate examples of attention, sensory strain and managing change. Ask what support is available for the needs that remain.