Shakespeare called them 'the slings and arrows of outrageous fortune', but 'hurdles' is fine.
Two tiny nits:
- If you're aiming for Am. English, 'defenseless' is right; the Br E has a c.
- 'behave like a man' would be better. I think it's compulsory for Am E, though a prescriptively-taught Br Eng-speaking pedant () would hold that it should be 'behave as a man would'