Get both on a 30-minute call and ask them to prioritize the tasks. I'm assuming you've helped estimate each task? If not, this is an excellent time to present

Get both on a 30-minute call and ask them to prioritize the tasks. I'm assuming you've helped estimate each task? If not, this is an excellent time to present it to the PMs. Unfortunately, I don't have a holistic view of your workload. This should reduce your anxiety and provide transparency to all involved.