1) any plan going forward has you working a few more years. I am going to use 55 as your goal now.
2) If you do this in the US, you will have 40 credits, so I would quit discounting SS from your plan.
3) If you have $6500 available, make your 2023 Roth IRA contribution in your new Roth account. Plan on doing that every year. This will increase to 7500 after age 50.
4) Pb4Ski spoke about self employed 401k . Max that out for the next 10 years of earning.
Now go look at your projections. Make enough money to be comfortable, and max the self employed 401 and the Roth.
It is a reasonable goal. Now look at things from age 55.
Unless you have really good history of living to the 90's in your family, you can use 30 years for your calculations.
You can start drawing from the Roth at 59.5, but virtually nobody suggests that and it is usually the last money to get touched.