Your bocal cork is loose. Here’s what to do. Get a good grip on the bocal and twist it out pulling straight up being careful if you have to force it out that you don’t hit the bend on something. The cork will likely crack or break in some fashion and either come out totally or part of it stay in the well. Once the bocal is removed, you can dig out what cork that might be stuck with a thin knife or wooden skewer or something non abrasive. If you had to you could use a needle file, but a nail clipper handle or the file thingy may be just right. You’ll then want to be sure that none of the cork debris is in the bore, so blow it out, wipe it out and swab the wing.
If the bocal has any cork left, remove it. Wrap the bocal with waxed dental floss until you have it built up enough for a good fit. You could use thick cotton thread or reed wrap thread. But dental floss is really easy as it sticks to itself. If use cotton thread you’ll probably want to wax it with candle wax or parafin. This will work as a temporary fix.
You don’t necessarily need to go to a professional bassoon repair person for a cork: any band or woodwind repair shop can do it quickly and inexpensively.