Today I went for a walk with my dog ​​for 10 minutes and in these 10min my female dog was attacked 3 times! She's neutered.

Not all at once, but always in a different place and by different dogs.
I have her on a leash because I know she doesn't like many dogs or is afraid of them. If she sees a dog she does not know or like, then she starts barking at it.
This would all be less of a problem if it there wouldn't be so many stupid people who let their dogs run off leash and are not able to keep their dog with them.

The first dog that raced to us today (Jack Russel I think), first barked it and then there was a brawl (no owner to be seen anywhere). I am turning in circles trying to keep my dog in the opposite direction so that they wouldn't clash. Since at this moment she would also like to bite back!

The second day was a dog on a leash and had a muzzle (thankfully). Tried to pass because I really could not avoid (2m only I could escape to the side). The owner could not keep the Collie on the leash after which she wrestled with my dog ​​again. If nothing happens, because he had a muzzle! And then the third dog which was off the leash ran towards my dog after she had barked at him.

Now my question, what shall I do in such situations? When I walk with my dog ​​on a leash and someone else's dog starts running over ready to bite her?
Actually, from what you've said, your dog is the aggressor. You have to stop her from barking at strange dogs. Other dogs will take that barking as a challenge and act on it.

As soon as she begins to bark at another dog, jerk on her leash or touch her with your foot to divert her attention, and tell her "No!" or "Quiet!" or "Hush!" Pick one and always use the same command, so she learns the sound and what it means. Keep doing it until she quits. If she is allowed to continue barking at other dogs, one day she will pick on the wrong one.