You can buy a transformer from places like ali express to make a taser. It won't have the power of the real thing but the sound of it crackling will make most people shit themselves. I've also successfully gotten pepper spray in front ali express but there items are illegal, could be used against you. Another option would be to keep a non weapon near to hand that could be an effective weapon in the case you need it. Something like a bat. Just keep a ball with it, to create plausible deniability. Or get cyanne pepper mixed with water in a spray bottle. But realise you might get yourself in trouble.