I understand your feeling. I've been in similar situations...

The trick is to ride further left into the lane at all times, not too close to the curb. So if there is an obstacle (joggers, kid who fell off his bike, parked alien shuttle) on the right of the road you'll be in a better position to avoid it.

Imagine the lane you're travelling on as divided in thirds. You have to ride on the imaginary line between the right third and the middle third. The cars will instinctively give you A LOT of space when passing you, which will give you more room in situations like this.

I also feel unsure about the bell, but you have to liberate yourself and use it a lot. Sometimes even if you're by yourself, just ding ding! it, and laugh. It's great fun.