See a therapist that does cognitive behavior therapy.

I had a terrible fear of flying after I was in a small plane that had a near miss with the tree line and a difficult landing into a lake. I started CBT to work through getting past the anxiety using various tools. I didn't stick with it. While I was doing this therapy my FIL was suffering health problems and we persuaded him to come live with us. He said that if he got on a plane he would die. We persuaded him that he would be fine and my spouse and FIL got on a plane to come to our home. He died on the plane. My spouse had to sit out part of the flight with his dead father beside him. I'll never fly--I quit going to therapy after he died. If I go to an airport to pick up my spouse my palms sweat.

But you love to bike. I don't give a crap about flying. CBT is work. It takes a good therapist. But it can be very successful.

I also like the idea of a trike--maybe you and your wife could get a couple of delta trikes. With kits a lot of them can be joined into tandems.

The other option is a crank forward, like a Rans, where you can stop with both feet flat on the ground.