[comprev]

With only 2-3hrs of time what can you realistically achieve?

[rl1987]

You may be overestimating the real amount of truly focused work that was done by many technical employees back in 2010s.

[HenryBemis]

I am also thinking to have a strategy/plan for something bigger in place.

You don't mention details of your health/medical situation, but while you get "the thing" that will NOW get you the $300 per month, perhaps you aim for $350 or $400, and in parallel start thinking on "what can I build that will generate (in two years?) a steady $300". So in 3-6 months you can use the extra generated ($50-$100 per month) to build some service, website, etc.?

[geraldhh]

that's plenty of time to achieve a lot and have a decent income. problem is, no one is offering it, you gotta take it

[herbst]

I wonder what I could archive would I actively work with full passion just 2-3 hours every day.

Imo that's plenty