I think that the New Moon on September 25th may have flustered the opposition from transiting Jupiter to your natal Mercury in your twelfth house.
The transiting Sun and Moon were conjunct your natal Mercury, which was also being opposed by transiting Jupiter in your sixth house. The sixth house and the twelfth house relate to health, where the sixth house has to do with physical health, and the twelfth house has to do more with mental health.
Having natal Mercury in the twelfth house suggests that you could already be prone to anxiety - which is essentially the root of OCD.
With Jupiter’s expansive nature, it can exacerbate what it touches. I sense that the New Moon activated the nature of the opposition between transiting Jupiter and your natal Mercury. I see tension of the mind within this aspect and (these) placement(s).
Your third house, house of the mind, is ruled by Jupiter (Sagittarius cusp), where your natal Pluto resides. One of the many things that Pluto is known for is obsession. Ketu (South Node) is in your third house as well (known to be malefic), conjunct Pluto.
The obsessive nature of Pluto and malefic nature of Ketu could have been activated during the New Moon due to Jupiter’s relation to your third house in your natal chart.
Your natal Mercury is also decently close to your Ascendant (separating at 5°), and the Ascendant is a sensitive spot in a natal chart, known to influence health.
So, I think that it was the New Moon conjunction to your natal Mercury, opposing Jupiter in your sixth house, that could have brought about the symptoms that you’re experiencing.
My recommendation would be to see someone who specializes in OCD if things haven’t improved in a month. They’ll be able to help you cope with the symptoms and manage them so that they don’t disrupt your daily life. It’d likely be better to go sooner than later ensure that symptoms don’t worsen.
I hope this helps and I hope that you see improvement in your symptoms.