I'm not understanding what the issue is about falling off your boat. That's something I was concerned about when I first started sailing 5 years ago but as you become more familiar with your boat, that concern deminishes.
Does that mean that you can't fall off you boat??? Absolutely not. It just means that you will soon be able to isolate the conditions in which falling off your boat is possible. The biggest question is "will the boat stop if you fall off?" I've found that falling off your boat usually involves some form of radical sailing (i.e. flying a hull, trapezing, sailing on a broad reach sitting on the stern of the boat). In almost all of those cases. if you fall off the boat, the boat is going to capsize. Also be aware that in strong winds, a capsized boat can even move faster than you can swim. For me, in those instances where falling off applies, my hawaiian righting line doubles as a lifeline. I make sure that it has a lot of slack in it just in case I need to reach for it.
I sail solo 90% of the time in the Pacific with 6 foot swells & 30mph winds and I can't remember a time when I've even almost fallen off my boat. That dosen't mean that it won't happen. That's why I keep my GPS & VHF in a sports fanny-pack at all times when sailing. This is mother nature we're talking about and nothing is fool-proof. My suggestion is to just go out and enjoy yourself with safety-first a priority and not to sail outside your comfort zone. Of course, it's a lot more fun when you do.

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