The modular route is your best option.
But before you spend any money obtain your Class One Medical. Or at least a Class Two prior to PPL training. Then a Class One before starting your Ground school studies. Critically important.
There have been issues transferring German issued medical records to other States. No doubt someone can provide the latest state of play please.....
You mention feeling "depressed" over the last few years......are we talking about just feeling frustrated at not being able to start flying or something you have sort medical advice about?
As for the environment, you cannot make an omelette without breaking the eggs. New bio fuels are within sight.
Aged 28 make your decision soon, and get your old physics books out. Boyle Law, Charles Law. Remember ?