Middle aged man looking to transition from driving to riding

I'm middle aged (mid 40s) commuting to work by my car. Have usual middle aged problems associated with a desk job, like sciatica, joint pain etc. Living in a tier I city where traffic sense is almost non existent. Takes a lot of time each way (to and fro). Looking for a bike that can handle my weight, preferably a cruiser, but not too low, like the avenger. Rides smooth over bumps and potholes. If it has an arch where the rider tucks in for better back support, even better. I would prefer a bike where I won't have to bend my back too much. Budget < 2l. But can extend it a bit if I get a good overlap of my wants and what's offered Thank you for your time