Hey Skip
So everything written above are good things to keep in mind with stance and body position/control when learning how to jump.
Now I'm going to give u something to practice to build confidence and a feel for jumping in different ways before just sending it.
You said that you are hitting side hits and falling but u said last year you were hitting jumps (I assume small park jumps)
The difference is, on a park jump you take off with your board flat. On side hits, you will be jumping off your toe edge or heel edge (depending on what side you're on).
It seems pretty easy, but if your not confident jumping off an edge you will end up on your face or your butt.
So to learn how to do this safely, try riding across the hill (across the fall line) and popping (jumping evenly off both feet) off your toe edge. Do a few little pops going across the hill and then turn. Now do a few little pops on your heel edge. Keep doing this until it feels pretty easy.
Then do the same thing, toe dge and then heel edge but try ollie-ing in stead of popping (ollie is like popping but you lift the front up first and kick off the tail to get into the air, but you probably knew that)
Popping is more stable but it's good to practice ollie-ing too.
Then go back to those side hits and SEND IT BRAAAAA!!!!
Let me know how u go!