Welcome to the Wefugees community and sorry for the wait!
We have had plenty of similar cases on our platform already, so I'm going to link the threads here for you :-)
I'm an asylum seeker and I want to marry my British girlfriend and move to the UK with her afterwards
How to marry my British girlfriend in the UK?
As Garry mentioned before, an option would be that your girlfriend travels to Germany in order to get married - since you are still in the middle of your asylum proceedings. However, have a look at the threads I linked, as there are visa options for people who intend to get married in the UK.
I hope these sources help! Feel free to contact us again if you need any further assistance.