Sounds like you're working with a massive gap between your driver and 4, i doubt the hybrid is going to fill it.
I would look into hybrid 2, 3 and 4 irons. You could probably get a hybrid 2 lofted lower than your 19 degree, so that fills that spot in your bag, then a hybrid 4 in the higher lofted range, maybe 22 and think about ditching the 4 iron.
The thing with hybrids though, and fairway woods for that matter, is that the degree of loft really only matters in comparing lofts across the same brand.
I would go somewhere that has a range or an indoor simulator, and try out a 2, 3 and 4 hybrid at the same time, same session, check your distances, and then buy based on where they line up with your 4 iron.
The hybrids are way more forgiving off the deck than fairway woods.
I carry a 3 wood and a 7 wood, and a 5hybrid and a 4 hybrid. If you knew the degrees on them youd say

But what matters is I have about 15 yards between each of them, and can blast them off the deck.
When I'm walking the back 9; hungry; too hot; tired; or too high, I feel much better with a 5 hybrid in my hand than a 4 or even a 5 iron.
I can choke down on it and give it a light swing and get the same carry, not as high of a trajectory, BUT
I can blast that thing out of rough like its a fukking aluminum baseball bat.
I carry the 3wood and will only use it off the tee if there is trouble in my landing zone or a narrow fairway--or OB on either side.