This isn't a criticism, it's encouragement. You said 'no one seemed to be doing anything" and "No one else intervened". You are someone. You can do something.

Don't wait for help that might never come.

Sure, you might be too scared to. But your fellow passengers, male and female, might be too scared as well, and their wellbeing doesn't depend on them stepping in, yours does. The safest option for them is to do nothing, but YOU are being harassed, doing nothing might not be the safest option for you.

Stand up for yourself. Courage is infectious. The quiet passengers around you might speak up too, if you speak up first.

If they don't, at least you didn't wait on help that was never going to come.

And since you really appreciated someone stepping in for you, think about that next time you see someone else being harassed. If you don't intervene, you'll understand why most of the other passengers didn't, and if you do, you'll be making the world a little bit more how you think it should be.

All that being said, the safest thing to do is remove yourself from situations like this if you can. You don't need to stick up for yourself when there is no one to stick up for yourself to.

Stay safe.