I think there are elements of OCD/perfectionism involved but many people on the spectrum have issues with Executive Function. Unfortunately this still seems to be a grey area even for the professionals studying it.
The main problems for me seem to be planning, prioritising and time management. I also struggle with completing things on time due to attempting to reach a perfect state too.
If the problem is something relatively simple, for example the "Bike or run and which route to use" question, you can pre-plan. Simply alternate the activity, you may want to write out a timetable or schedule to train yourself. The main effort required is sticking to your plan and not deviating.
For more complex situations there are a few things that I try to use.
One is mental compartmentalisation. It's a visualisation technique where related subjects go into a specific area, room, box or pressure vessel in my case, and are sealed. You control access to this area and go there when you want to, rather than allowing these thoughts to interfere with what you need to do immediately. Again this, obviously, needs to be practiced and takes some effort but is much more efficient than a waterfall of thoughts passing through your brain.
You could try some basic meditation techniques to clear the thought processes when you are feeling overwhelmed, just focus on nothing for a while. It does not need to be for long 10 to 15 minutes. I find this works best with classical music, as in no lyrical content to focus on, and helps to reorganise the compartmentalisation technique.
If you find you are stuck on one mental thing, take a break and do something physical instead. As above just 10 to 15 minutes. Take a quick walk outside, yoga, martial art forms for example. I do core strength exercises as I suffer with back problems, but can recommend for anyone. This needs concentration and does not allow mental room for the issues that are bothering me.