International estranged father seeking wisdom from those who have been in a similar situation

Hi everyone,  I had an unplanned pregnancy while in Germany several years ago with my girlfriend of 3 months, she had decided she wanted a baby and I wasn't quite privvy to that. She also told her friends that I seemed like a retirement option.

Those details aside, I want to keep in touch with my son and be the best father I can be, but his mother is incredibly difficult (Kompliziert) she moved to a neighbouring country, didn't tell me and has ignored all of my correspondence for the last couple of years. She has ceased all contact with her mother and her brother also, not just me, for unknown reasons.

I do not want to go down legal avenues as the German state has a strong maternal bias, even though the legislation relatively recently was brought into line with the EU Court of Human Rights, to afford some rights to fathers, the modern legislation hasn't quite shifted the cultural norms and expectations or practices. I would be willing to explore legal avenues down the line if the situation does not improve, however I understand how stressful this can be for everyone and I will avoid it unless I am forced to go that way.

I am looking for wisdom from others who have been through such a situation, how to emotionally deal with it, best courses of action, sage nuggets of wisdom to help me through it. It's a difficult situation to be in. Even if you know someone who has been in a similar situation, how they got through it, or how they are navigating it, their advice could greatly help me navigate it.

I have easily found a lot of information on common domestic situations and custody however have struggled to find information specific to my circumstances of international estrangement.

I have seen my son a handful of times, and not since he was six months old, besides a couple of Facetimes. He is now 4 years old.

Any help or connections with those who have been through this would be incredibly appreciated.