slowfoot said:
...i realize it 'll take a while to develop the ftp to hang tough ...
Some races will come down to pure sustainable power, especially if they have long climbs, but you should be able to hang in flatter races if you work on your pack riding skills. Hanging in the pack often comes down to "gap management" it's usually not the steady pace that gets you if you're good at drafting, it's the surges that get ya.
Practice riding a wheel a bit off to one side or the other so that you can see up the road to keep an eye on what's coming and what the front riders are doing. It's safer since you'll see road debris and corners coming but it also allows you to ramp up to speed a bit sooner when the leaders jump or someone takes a flyer up the side. If you can get a bit of a headstart on the windup (without running into the wheel in front of you) you can use a lot less energy getting up to speed and avoid huge out of the saddle efforts on each surge.
I'm always amazed at how many riders simply wait for the guy in front of them to jump and then have to jump hard to stay on the wheel. A lot of times you can just start winding the gear early up while staying seated and match the speed with a lot less effort. Every once in a while you get stuck behind a rider that reacts slowly or for one reason or another doesn't react at all. Then you'll have to dig deep and go around him, but save those big efforts for when you really need them not in response to every pack surge.
Also look for the easy opportunities to advance in the field. If you're not right at the front (which you shouldn't be if you're currently getting dropped) then you'll typically be losing ground as riders move up around you. It's really tough to move up when the group is going fast and strung out and you'll waste a lot of energy advancing during those high speed sections. It's also hard to advance when the group is going slow and all bunched up with few safe holes to move through. But right between the surges and the slow sections there's almost always a short window where moving up is a piece of cake.
Just as a group is chased down or the pack slows for a moment folks tend to just coast or even feather their brakes as the fast strung out group slows back into a bunch. If you're paying attention it's really easy to just pedal a few more strokes while others are coasting and move up a few positions with almost no effort. Keep an eye out for these opportunities and use them to hold a position near the front.
That's just a starter, but there are a bunch of tricks to saving energy for when you really need it. If you need to take a short pull to stay up front just roll steady for a bit, don't kill yourself and get yourself dropped but don't refuse to go forward either. Often a short steady pull is all it takes to maintain your position near the front and discourage others from trying to drop you.
Good luck and stick with it,
-Dave