I've been hit by a car and crashed numerous times, breaking bones, dislocating a shoulder, destroying my bike, etc.
First, I absolutely love cycling soooo much and really don't intend on giving it up. However, I completely understand where you are coming from and I want to point out what I have changed and learned to make it a better, and safer, experience.
1.
I treat every driver like they are a complete idiot. If I'm cycling down the road and see a car at an intersection waiting to turn or go straight while I have the right of way I immediately start signaling with my hands that I intend to go straight or turn, if I see that they notice me, and nod, or something to that effect, I will continue. If they don't acknowledge my signals or I genuinely can't tell if they see me I start braking, even if I have the right of way and carefully watch to see if they start moving (without seeing me). Even if I have the right of way, I will absolutely yield to a large vehicle that doesn't see me, I won't get angry at them, as we're human, and no one really has 100% focus 100% of the time, that's life.
Had I started cycling with this philosophy I probably wouldn't have gotten hit because a person turned into me while I was careening down a hill, I would have carefully watched them, saw that they didn't see me and start slowing down. Not speeding up to try and make the slowly closing gap between them and the curb (I vividly recall not making that gap, then waking up in a haze 30 feet from the impact... not a great day).
2.
Ride with others. Large fast A rides can be quite dangerous with everyone trying to make lights, barely stopping at stop signs, riding 4 abreast, and exhausting themselves to the point of hysteria on every hill; BUT
small training rides, maybe just you and your best friend make you a much easier to see and gives me far more confidence around vehicles.
3.
Know the roads. First and foremost, I do not ride in the city, if I do, it will be on a dedicated bike path away from traffic. I will do whatever I can to get on my lonely country roads with large shoulders and smooth tarmac. I also LOVEoutrageously long rides, like 150mi+ and I meticulously plan them
around high traffic areas.
I use google's traffic feature, set it to "typical traffic" and plan my route on where the traffic will be when I will probably arrive in a particular location:
Whenever I set up a route I make sure I'm not on state high-ways, they are always bad news—if I'm going to be on any road (even a lonely country one) for a long period of time I use google maps to ensure they have a nice shoulder.
Now, I've read your posts before and it sounds like you predominantly ride in an urban city area with iffy traffic and pretty dangerous bike lanes. If I were in the same situation, I would probably change my road biking habits and do the following:
1. I would invest heavily in indoor biking, I'm already a big-time zwifter, but if I were stuck in the city and couldn't move, I would get a very very nice direct-drive smart trainer, perhaps even one of the new stationary bikes like the Wahoo bike. I would setup a gaming computer connected to a large screen (or projector) and Zwift
a lot. I would also use Rouvey and Trainerroad to mix it up. This is what I would do throughout the weekdays when I normally only have opportunities to bike between the 1-2hr range.
2. On weekends, or whenever I have time for much longer bike rides (50mi plus) I would load my bike into my car, drive out to a destination, and ride a route that I meticulously setup to give me the best possible experience. Even though I live near plenty of nice country roads, I already happily drive hundreds of miles away, if I have time, to make an adventure out of some new roads.
Just my thoughts, hopefully, you can enjoy yourself soon!