I'll be direct here
Doubting yourself on this design is a good thing
Especially if you had ideas to use that exact script in the tattoo
On the positive - the idea of a getting a tattoo that symbolizes your struggle with OCD sounds like a cool one - but I think you should go with some imagery rather than text
And this next part is quite important - find a good artist
You've done the right thing coming here to ask some questions
Tattoos can be fun and impulsive things and work out just fine
But most of the time - it's better to slow it down and do some thinking and researching
It seems this is a case where you did have some doubt and it helped prevent you from making a bad decision - just my two cents - keep us updated
