I know you're asking for practical advice and for that I don't have much to offer. But I do notice a lot of assumptions and judgments in your language which may not be true. There is no such thing as a 'dead end' in a career, that's just a thought you have. Same with the idea that you can't code for the rest of your working life. Or that 35 is old.

These are all just thoughts you have which very well may not be true. Why don't you dig into those thoughts, why you have them, and see if you can think about them differently.