I have a real problem with the German embassyMy...

We would like to inform you that if you applied to German visa and was rejected, then yes you can apply again but we advise you to find out the rejection reasons to avoid that again. Note that grating visa decision depends on the embassy and no one can force them to do other things. It is clear from your question that you didn’t provide enough guarantees to return. So we advise you to appeal against the rejection during 30 days of the rejection to find out the reasons and you can convince them that you will return if you have residence in Egypt, so you can provide letter from your work to prove that you are still working and clarify the salary. So the court of the embassy may edit the decision and grant you visa.
Note that if you were rejected even after appeal, then you can’t apply for visa again unless after 3 months\90 days and you have to avoid the rejection reasons.