Welcome to the Wefugees Community and thank you for reaching out to us.
I am sorry to hear that you are in such a difficult situation. But it is also quite impossible to give you any advice without knowing your personal situation in detail or being familiar with your background. However, from my perspective, staying in illegality is not a sustainable solution. That is, why I would highly recommend you to get support from a lawyer or visit a migration counselling office to discuss your options. The social workers and migration experts offer their services free of charge and work confidentially. You don't need to worry that they might report you to the authorities or something similar. Please let us know if you need support in finding such an office close to your current location. In any case, it is good that you acknowledged the fatherhood (Vaterschaftsanerkennung) already as this might help in future to apply for a residence permit as father of a child with a residence permit, for instance.
Fingers crossed for everything and please let us know if you there are any further questions.
All the best,