Hi,
No, you don't sound stupid at all. I used to live in Clapham Junction, before it became fashionable, it was gritty and hard. I then moved to West Hampstead, a great part of London, very safe & secure.
I'm probably going to take some flack for this, but: Another solution to Mace (which may be illegal to possess and to use) is to carry almost any industrial strength spray cleaner, strong smelling cheap perfume, or even hair spary, when sprayed into someones eyes will, both scare and hurt them. Depending upon what you use, it may or may not cause permanant damage. A litle hair spray feels awful (my sister once sprayed me with it when I was being a brat) but it won't cause blindness, and you can't be accused of carrying anything illegal !!!
On the down side....some guys might want to exact retribution for you hurting/humilliating them....what's the best solution? To feel like you're taking control of the situation? Or to continue being harrassed? Personally, I would choose empowerment.
For the record, I'm a 6 foot tall, 200lb guy, an ex-bouncer, construction worker, and if anything goes in, or near my eyes, I cringe and run for the sink. I have no experience harrasing women (apart from my 3 sisters) so I can't say what goes on in the minds of a pervert, but most people when confronted publicly, will run away. Another thing you could do, is tell them you're a Lesbian, tell them you have AIDS, Herpes, etc. Last resort, kick them where it counts, hard; and run away.
N.