Thank you for sharing that story.
One thing you might consider is looking into either distressed properties or working with a builder to build new ones.
If you buy distressed homes you could use the BRRRR strategy to not only fund the acquisition and renovation expenses but also create working capital with each one you do.
Consider this. Acquisition Cost $150,000 + $50,000 rehab = $200,000 invested. ARV = $275,000
Refinance the property @ 80% ARV = $220,000 = $20,000 net (minus fees of course)
You have now purchased the property, paid yourself back the renovation expenses, put $20,000 ish in the bank and provided your Son with a space he can then cash flow.
The same would apply if you found a builder, or modular home, purchase a lot in a desirable neighborhood where the ARV would suggest you could profit from building a new home there. Then you do the same thing. You acquire the land, place a home on it that fits the needs you have, finance it, pay yourselves back and repeat.