Oh, hon, I'm sorry you're feeling so frustrated. As I write this, I know with certainty that my daughter will wake up from her nap in about three minutes. I also know that I will not try to get her back to sleep because she will end up screaming bloody murder and I will give in and get her up and we'll both be cranky as a result. If I just get her up, then I won't have such nasty thoughts about motherhood.
My saving grace is that regardless of whether Kenzie sleeps for 45 minutes or for 2 hours (when was the last time that happened, anyway?) she can stay awake for the same amount of time, about 2 hours. So at least EASY isn't completely ruined like it was when she first started the short naps.
But I do feel your frustration. There were too many possibilities of why Kenzie is having the short naps and too many possible solutions and I was just going crazy with experimenting and trying to figure out what was going on. Like you, we've been dealing with it for two months. The best solution for us is to just get her out of bed and be thankful that she sleeps well at night. I'm not saying that you should give up trying to extend naps if you think you really need to. But just know that you're not the only one who hasn't found a solution that worked, and it's not a reflection on your value as a mother.
Ah, someone's awake! Gotta go. Hang in there!