I see this thread is a couple months old, so if you are no longer thinking about this, I apologize for the bump, but in case you are still looking...
For many years I've carried a four inch sometimes three inch revolver or some form of 1911, but do to health reasons I've been thinking I'm going to maybe go with something much lighter. I wish I could be happy with a little pocket 380 or 38spl but always feel the need for something more accurate and capable of making regular good hits at 40-60 yards if necessary. Rural farm type area, I've had more trouble with feral dogs and critters than anything else but there is still no shortage of meth heads in the area. Anyone one else make their regular carry option on the possibility of the occasional longer shot.
I do not expect to need to take a long distance shot. Ignoring the should you that so many here have commented on, most self defense needs are short distance anyway (sometimes extremely close distance- I'd worry more about how a gun is at contact distance than long distance, part of why I used to carry a snub when in a carry state since it won't go out of battery if I'm so close to my attacker that the gun is pushed up against him). At longer distances, the chances of getting away/hiding behind cover or concealment is better, and I'll do that if I can. Still, with the occasional mass shooting hitting the news, and occasional concerns of a DC sniper like situation, I do see more and more people online considering guns that would make distance shooting more realistic.
All that said, practicing for distance shooting with your self defense gun is probably a good idea. You never know what is coming, and the better prepared you are for anything, the better. Also, if you are proficient with your gun at 50, 75, 100 yards, the more likely you will be accurate at the more likely 1-5 yards of the typical defensive shoot.
So, all that said, considering your problem of wanting a gun you can shoot relatively long ranges, but needing a smaller/lighter gun due to health reasons, here are some suggestions. You don't need a 1911 or a service revolver to hit at 50-100 yards. With enough practice any gun will do. Still, I see from your post you want something easier than a 2" snub or a pocket .380. If you need to cut back for health reasons, I'm assuming weight more than size is the issue. So, why not a polymer 9mm (if recoil is a problem), or if you prefer a larger caliber a polymer .40 or .45? I'm not really a Glock guy (I don't own any) but since they seem to be the standard in polymer, a full size 9mm Glock 17 weighs only 25oz unloaded and even fully loaded with 17 rounds of 9mm it is just over 32oz (still several ounces lighter than your empty K/L frame revolver or steel framed 1911), the smaller G19 is under 24oz unloaded (and around 30oz loaded). The .40S&W versions don't add much to those weights (an ounce or two), and even the .45ACP pistols are pretty reasonable. If you really do want to go small, my SIG P290RS is nearly a pocket gun, yet it doesn't recoil too badly, and it is as accurate as a bigger gun. A more traditional SIG P239 (hammer fired) or Kahr K9/K40 could be a terrific option if you want something small/light but you prefer metal over polymer.