What follows is my reply to a student having great difficulties with this part.
Do use a metronome, but don’t change any equipment whatever you do.
The phrasing of your problem means to me that it is in your head in such a way as to become an obstacle, which this piece is not.
Without hearing you play, I would suggest that you simply listen to several recordings of it. You almost never hear the clarinet through the crescendo that the orchastra is making. The time is more important, that is the arrival at the cadence point with the others. Exactly at that point, which requires watching and keeping your time with that of the conductor and the orchestra, which sometimes can be at odds, one with the other. Keeping in time with the ensemble is most important.
Don’t make it a tonguing contest. That is not what playing music is about, ever.
Being comfortable with the ensemble in terms of time is most important, and the articulation will definitely come, much easier than you think.
When you say “I can’t play the Beethoven 6th Scherzo”, I say,” yes , you can”.
Even in your practice room, you must hear the orchestra and know as many of the other parts as possible. When you get into the group, you get used to them and it can be a wonderful experience, a kind of symbiosis takes place and all help one another.
As in many clarinet parts, your particular part is not what is most important. In the Beethoven, it is taking over the solo line from the oboe and then staying with the others and of course, the conductor. The staccato will come, of this be certain. Ask yourself, “what is the tempo?”
Then you are quite close to the achievement of you part.