Hello.
An earlier answer of mine on similar subject may also be useful.

https://clarity.fm/questions/6349/answers/20321/share

TAM is a useless number here. What is more relevant is what is the immediate market size that you can operate in - say in the next 3-5 years - Total Capturable Market - TCM.

Right now my sense is for you to to create a value proposition or positioning, and then develop a prototype, validate with design thinking principles, define scope, develop MVP, get paying customers, and then execute per the plan recommended in the link above.

I think you are trying to jump from an idea and TAM to an MVP without going through the stepping stones to the same.

Hope this helps. Bye.