Road riding can be dangerous sometimes, and you should talk to your partner about it. You should not be lying or underselling your story, because what I read from your post is that you are freaked out, too. Your wife will be worried, because she loves you and because she can tell that you were scared. That is normal.
I deal with this combining a number of issues: I live in a big city and it takes me about 20 minutes to get out to calmer back roads. One big issue with cars is that they underestimate my speed. The speed limit in Japan in the city is 40 km/h for the most part, and I can reach that speed on a road bike or get very close to it at least. Most of the closest calls I have had were drivers who wanted to overtake me in the most inopportune situations.
So here is what I do to lower the personal risk: (1) Route choice and timing is probably the most important factor. That takes some experience, and you can’t necessarily just follow the routes suggested by Strava or whatnot, which are great on paper, but could be suboptimal. I try to get out of the city quickly and to calmer roads. Timing can also be crucial, sometimes there are predictable traffic patterns flowing in one direction or another.
(2) Defense is my best offense. I ride very defensively when there is traffic. In the city I try not to ride aggressively and use my knowledge of some of the idiosyncrasies of Japanese drivers to my advantage. E. g. they use turn signals very, very late, so I don’t just squeeze by after the light has turned green. Anticipate some of the stupid things drivers might do. If you are chasing average speed, push the lap button as you exit and enter congested areas so that you are under no pressure of hitting e. g. 30+ km/h on your trip. I also don’t try to curse at drivers.
(3) Part of your defense is being visible. Don’t be on a black bike in black clothes when it is quite dark. Wear some high-vis clothing (e. g. I have an orange POC helmet), something with reflectors (most jerseys come with them) and use lights also during the day.
(4) Try to get something like a Garmin Vario radar and/or mirrors. Yes, perhaps mirrors look dorky, but they keep you alive. My road bike is pretty much perfect, on of the few upgrades will be a Vario.
(5) I do not compete for downhill KOMs. I have a family and don’t want to end up as an organ donor. Perhaps this isn’t directly included, but should be. If you are rushing downhill, you can easily get faster than a car, and avoiding all sorts of close calls because a car is taking the switchbacks at glacial speeds.
(6) Be excellent to drivers. Thank them. Often. I use a hand waive and thumbs up liberally. Give them clear signals (e. g. our team uses stop when we are in a peloton and want to signal to drivers that they should wait even just to remind them of what they are supposed to do — we of course don’t cut them off).
Lastly, if you still feel that this is too dangerous, try mountain or gravel riding.