I had a very similar problem and adding some tape fixed it right up. I was grabbing the ball since the thumb hole was too big and it caused a raw spot on my thumb exactly where you are describing.

Welcome bchinfoon! I agree with the tape idea. I had the same issue and black tape on the nail side of the thumb hole fixed it right up. Smoother release and less grip. If that still seems like you're squeezing you could try the white textured tape on the pad side of the thumb hole. I had to do that for a ball of mine as well. Secondly, I just want to concur with you on the physical description! I myself only weigh a whopping 118-120 lbs lol! I started with a 11# ball originally and felt it was too light once I had it fit properly. the ball typically feels about 1 pound or at the most 2 pounds lighter when fit properly and eliminating squeezing. Now that I've been bowling for about 7 months and have been hooking the ball for about 6 of those, though I still have a lot to learn I like to think I picked it up pretty quick lol, the ball feels much lighter. Muscle and muscle memory in the wrist and forearm take time to build. Since I would assume we are both of a similar body build you might noticed that on the arm you bowling with, your forearm might become literally a bit larger and more defined, noticeable to you at least, mine did. I'd check the thumb fit of your current ball, fiddle with tape, get to the point where you don't have to squeeze, and practice until 14# feels comfortable. It takes time just like working out at the gym

Thanks for all the advice! Things are slowly getting better as time goes on. I'm thinking I may want to get something slightly more aggressive for my next ball. Any suggestions in case I decide to pick up another ball somewhere down the line?

The L-Link is designed for lighter oil so a more aggressive ball would be a good idea. If you like 900 Global, then I would suggest the Break, the Break S75, or the Creature. Any company or balls you had in mind?

I don't think I'm partial to brands. I read a lot about Hammer Black Widows, but I'm wondering if those might be too aggressive? I think if anything I'd like a Storm, Hammer, or Brunswick.

The Widows are all really great balls. If you ask me, I think that the first Widow is the best but I'm sure others disagree. The BW Pearl is also a pretty strong ball. I'm really not impressed by the other two Widows. Storm has some good balls out now as well, the Hy-Road and the Virtual Gravity are hot new balls right now. The Rapid Fire balls are pretty good as well.

I think as far as a new ball goes, I think your best bet would be to have your Pro Shop (or a certified coach) watch you bowl for a little bit, as the ball should fit your game, rather than the other way around. I think if you do this, your Pro Shop opperator should be able to recommend something that will fit within your game, and will help you out the most. At this stage in your bowling career you don't want to get something that you have to alter your game in order for it to be effective. Just a thought.

Same thing happened to me. I had to fit it with some extra tape and it was fine.

Let me tell you, Bchinfoo, I've been there. It took me months to rid my abrasion problems. It was so bad at one point that it took me 5 minutes to tape and glue up my thumb before practice. Over time it got less and less severe. Now I'm protection free!

It's all about your release and at this point in your career you're probably doing a million things wrong. As you get more practiced and accustomed you'll be able to a develop a cleaner release.

Depending on how serious you are about bowling, I recommend getting some professional help just to push you off in the right direction. Otherwise the internet is full of useful information. With practice and knowledge you'll be able to develop a great hook and an unscathed thumb.

Your best bet, and the quickest way to improve, is to get hands-on instruction. Reading and watching videos can only go so far. An instructor will pay for the cost in the first session.
He will check your ball for proper drill.
He will check your span and hole fit.
He will teach you proper steps, how to hold the ball, and how to swing.
Most importantly, he will show you what you may be doing wrong, and how to correct it.