I am sorry to hear about your problem.
In this situation, please make sure that your Animation Blueprint is implemented correctly. You can perform this check by debugging it. For this, please open your project in the Editor, go to the Content Browser, open your Animation Blueprint, click on Play and select the appropriate instance in Debug Filter:
Then, press Ctrl in your game and look at the Blueprint. Please make sure that the appropriate state transitions occur. If they do, check whether Animation Sequence (or Blendspace) is correctly set for the crouch state.
If transitions don’t happen, go to EventGraph and check whether corresponding values are set correctly.
I had a similar issue. Turned out that the animation blueprint was casting to the original name of the blueprint. Which was not what my actor was named, so the animations didn’t apply.
I’m still pretty noob to UE, so I’m not sure if there is a quick/easy way to change references, but so far this seems kind of lame if you want to apply the same animation blueprint to different characters.