is there a good proper global medical insurance, i am not talking about 30 days travel insurance
for example I live in ukraine, europe and russia frequently travel for many months
There are plenty of companies offering global yearly plans. But they mostly insist you update your address after each move. If updating address is not a problem after each move simply punch your details into the below sites quote tool and pick the level of cover and provider you feel comfortable with. Most of the major global providers are listed there.
there is a big difference between nomad insurance and travel insurance, getting a solid travel insurance is trivial - but the premise of that insurance is that they will patch you up for critical things and transport you to your home country for extended/complicated care.
If you don't really have a base anywhere you're looking at international health insurance which becomes a slightly more complicated thing depending on what coverage you want, where do you plan to spend time etc.
Personally I use Home, they are pretty good at finding you a fitting deal and take care of the heavy lifting through the process.