I think that a 99 Silverado is the NBS truck and his is the OBS truck.
You can try
THIS howto to remove the door panel.
The outside door handle may be broken, look for cracked plastic on the outside. Or it may just be a bent rod. Look for the door handle release rod and see if there is any more adjustment that can be made to tighten it up, once you have the panel off.
Did it suddenly let go this morning, or was it gradually harder to open over a week or so until it just stopped opening?
Mine did the gradual hard to open from the inside, had to pull harder on the handle, etc for about a week, until one morning it stopped completely. Turns out I had a broken outside handle. Replaced the assembly and it's been working great ever since.