Hey Christian. Welcome to IOTA!
If you are pretty confident that you know what most of your seed is, then there's a good chance you'll be able to recover your IOTAs. You'll need to bruteforce your own seed; normally this would be impossible, but because you already know most of your seed, the number of possibilities that you need to guess are diminished significantly.
Another user had a similar problem, and he was able to recover the original seed:
You'll need to make contact with a coder that you trust who can write a program. Starting with the seed that you copied down, it will "fuzz" the seed (trying random-ish variations, probably with some optimisation around using letters that are collocated on your keyboard) until it finds one that generates the correct address.
There's a catch though; whoever runs the program will be able to recover your seed, so:
- Make sure it's someone that you trust, and
Immediately transfer your IOTAs to an address generated with a new seed once you recover them!