I understand that cyclists slow drivers down, but why can’t some drivers at least try not to kill them?!

I’ve been cycling to work now for the past couple months (sold my car to reduce bills). I do everything by the book to ensure I am as minimally hindering to drivers as possible, I hug tightly to the curb when on the road, use cycle lanes whenever they’re available, never undertake and regularly pull in to allow cars to pass. However I’m still constantly facing near misses with cars that decide to overtake with mere inches to spare, take sudden left turns immediately after overtaking me or pull out in front of me. The other day I was cycling down a hill where there is a left turn onto a slip road, the cycle lane also splits in two to allow cyclists to either continue, or turn left down the slip, so drivers must pass over the cycle lane to go into the slip lane. I held my right arm out to indicate that I was continuing straight, yet the car to the right of me which had started to overtake turned left anyway knocking me off my bike whilst I was in the cycle lane. They didn’t stop (nor did anyone for that matter, just heard a few beeps) so I just got up and carried on, fortunately I only suffered a few bruises. I wish that cycling wasn’t so unsafe, I only started so my girlfriend and I would have more money between us. I’m not one of those arrogant lycra ninjas, I just want to get to work 😭