Most important is to see a private bassoon teacher, who can fully assess what is holding you back. Here I can only give very general advice. Of course it's crucial to have an instrument and a reed that can play those notes. Beyond that, and having the right embouchure and breath support (and the right fingerings!), it's mostly a matter of lots of slow practice. Hope that's of some help!
What tempo are you taking this?
I also have to play this and I'm having trouble being more comfortable in the higher ranges, any suggestions?
Most important is to see a private bassoon teacher, who can fully assess what is holding you back. Here I can only give very general advice. Of course it's crucial to have an instrument and a reed that can play those notes. Beyond that, and having the right embouchure and breath support (and the right fingerings!), it's mostly a matter of lots of slow practice. Hope that's of some help!