Boggs down

Any check engine light? Did this just start or has it been slowly getting worse? It sounds like it could be a couple things. One would be low fuel flow, the flow and pressure can keep up at low power but not when you need more fuel. To check that you do a fuel pressure test.
https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

The other could be a partially plugged exhaust system. In this case that would mean the exhaust can get out when it slowly builds up but when you open the throttle its flow is not enough and the engine chokes.
For that an exhaust back pressure test would show if it was an issue.
https://www.2carpros.com/articles/how-to-test-a-catalytic-converter