Hi macabe and welcome!
I am wondering if anything else has changed? Have you added/changed any other precriptions? Even natral suppliments should be considered here, as they can cause reaction just as Rx's can.
Any major lifestyle changes? Exercise, diet, weight loss...alcohol/substance use?
Just things to consider...otherwise, if you doctor is not concerned...I would just stay the course of splitting the pills and go with the half-dose.
I hope that you get the answers that you seek soon. Perhaps someone with similar experiences will post and share.
Keep talking with us. We are a supportive group here to understand and listen.;)
Scaredy Cat