I started to learn Dutch and Schweizerdeutsch (swiss german) simultaneously and I found that the way I speak german in general has changed in terms of pronounciation and in next november I will have my test DAF exam, I'm afraid that I will fail the exam because of my accent, because my speech will be recorded and listened to later which in my opinion will make the matter worse, so how would I get rid of this accent while speaking standard german and use it again when speaking Schweizerdeutsch, because it is hard for me to say for example "ich" and "ich" as a swiss might say it without mixing both. I also read that having such an accent in the exam will not make any difference, is that true? And how would that sound to a native german from Germany or Austria?
Swiss accent is no reason to fail an exam: Swiss-German is as valid an accent as any one.
They can't make you fail because you speak like millions of German native speakers. However, it will not be beneficial, if your examiners have a hard time to understand you (and maybe fail to identify the kind of accent!). Beware: If you speak dialectal Swiss-German and not "Schweizer Hochdeutsch", you may rightfully fail.
I suggest that you try to inform your listeners that your accent is Swiss. If you still have the choice, I would also recommend that you pass the exam at a test center in Switzerland or at least Southern Germany - and not in Berlin or Hamburg.
(Personally, I acquired my DELE diploma from a test center in Germany instead of Spain to reduce the risk of failing the oral part.)
I remember an interview with a renowned Swiss-German author. He had been teaching German to a Japanese student. The student, who needed the exam to enter diplomatic service, failed the exam: Admittedly his German was excellent - but all his relative clauses were introduced with "dass" instead of "daß" (as required by old orthography in Germany and Austria - but not in Switzerland). The author said that he had contacted the test center and/or the Japanese Foreign Ministry to take the responsibility for the failure on himself, tell them that the student had written correct Swiss-German and make them reconsider. (Outcome not mentioned or forgotten.)
Assuming you're referring to the TestDaF Institute, on their web site they say (emphasis mine):
Ihre kommunikative Kompetenz ist also wichtiger als die Wiedergabe z. B. grammatischer Regeln und Strukturen. Wichtig ist, dass Sie sich mit dem Format des TestDaF vertraut machen.
Translation (by deepl.com):
Your communicative competence is therefore more important than the reproduction of grammatical rules and structures, for example. It is important that you familiarise yourself with the format of the TestDaF.
Thus I doubt you'll fail the test because of having an accent.