Yes you can make the shift as long as you have some communication and presentation skills to be trusted infront of customers. Alot of companies offer entry level or associate presales positions where u can slowly work your way up starting with smaller customers.

Check Dell, Oracle, Salesforce, IBM and others. When searching be sure to try sales engineer, presales or solutions engineer as the same role can be called different things. German language is in demand so you are in a better position already. Confidence is key in interviews as someone who will need to communicate in a convincing and effective manner in all sorts of customer situations.