I tried to conquer my fear of riding a bicycle last year but I think I've given up that hope... for now. I've been looking into getting a tricycle. There is a bike shop about 20 miles from here that has lots of different type of bikes available including tricycles.
My main issue with the bicycle is I feel high up and I feel like I'm going to fall and hurt myself. I have some stability issues normally but I just can't get over my bicycle falling fear and it makes riding a bicycle not enjoyable.
My concerns with a tricycle are:
1) Cost - some seem very expensive but others seem reasonably priced
2) Transport - I'm not sure how our car would transport a tricycle. When we've transported bicycles, we've taken the front wheel off and put them in the back of the car (small suv).
3) Path usability - A tricycle is wider than a bicycle but with a bicycle, I never got close to the edge for fear of going off the edge. I think with a tricycle, I may be able to get closer to the edge.
4) Terrain - I'd like to have a tricycle that is equal to a comfort/hybrid usability on terrain. I'd mostly go on smooth paths but occasionally would like to traverse some gravel paths. Not sure if this is possible.

So I started looking into one of those 3 wheeled ones. I got mine on the Walmart web site ~ it was shipped to the store. They even assembled it for me at no charge. My son-in-law brought it home for me in his pick up. It can fold, but I've never tried that. I think you could ride it on a gravel path.