My son has TS and also OCD. What you have explained sounds like the type of OCD my son has. The ocd with the intrusive thoughts is called Pure OCD.
It took us two years to find this out. It's more hidden then the so called normal ocd where you see people doing the compulsions. You can google it, pure OCD, or Purely Obsessed. It will be very informative to research.
I find so much more out on line then I ever find out from the Dr's.
Taking two meds, one for the tics and one for the ocd thoughts works pretty well on my son. Although i have heard taking tic meds can make OCD worse and vise versa. Which i have seen a little of.
Have a great day