I have experienced similar problems. If fact I gave up guitar for years because of it. A few years ago I started seeing a great Physical Therapist. I am now playing again and PT is why. I do still get pain if I play too long, so I avoid pushing too hard. But the bottom line is that I am playing again and I am loving it.

Did the PT you went to specificly look at the problem you are having with your little finger, or did they just look at the elbow injury? Did you discuss the numbness with them? Did they watch you play the guitar? If they didn't look at the pinky specificly, there may be more that they can do. But you have to be active about getting them to focus on that problem, or they may miss it. They are not trained in mind reading.

Good PTs are capible of some pretty impressive results. Look for one with a Sprots Medicine background. After all, being a musician is really just being a diffrent kind of athelete. Also, if all they want to do is sit accross the room from you and talk about exercise, find another PT. The good ones are HANDS ON practitioners who can work some impressive magic. The talkers.... are not so much so.

Alternating Ice and heat packs to the injured area after practice has also helped me to keep playing. Talk to your PT about this as well.

I am now working on keeping my left wrist as straight a posible when I am playing. This seem to reduce how inflamed my elbow and wrist get when I play.

If all else fails maybe you could consider Open Tunings or Bottleneck Guitar.

Considering your small hands...maybe you would also benifit from a smaller guitar. I have a very small friend (around 5 feet) with small hands and a smaller guitar helped her.

Hope this helps.