J.C.
Hi J.,
I know how you feel, my daughter also 4.5 months does the exact same thing, 30 minutes exactly, it's like she has a built in alarm clock. She has been doing it for a few months, and also doesn't sleep through the night. I think it's completely normal, frustrating as it is (never get anything done).
Good luck, if you have any success let me know:)
congrats on the long awaited baby boy
Jessica