Scared of new medication

Hello, I'm new here,so bear with me.
I was diagnosed 2 years ago ,with concerns that I may have Parkinson's+ .
Approx 4 months ago I also started with Gastric issues,which I now know is Gastroparthesis and is connected to my Parkinson's diagnosis.
My neurologist also wants me to start a new( to me) medication called ONGENTYS 50MG one per night.
I am scared to start this as the possible side effects are frightening.I feel so poorly with the Gastrparathesis,I don't know how much more I can take ?
So does anybody have any experiences of this drug?
Could it actually help the Gastroparthesis?
I don't really know why I'm starting this med.! And keep putting it off.
Advice please