Thank you for your query.
Having an orgasm after intercourse only improves your quality of life, does not affect it.
The pain in the tailbone could be because of vigorous sexual intercourse, but normally, intercourse should not be very painful, unless it is anal sex or deep penetrative sex.
Other reasons could be mild trauma / hairline fracture
of the coccyx
could be a reason.
Deficiency of calcium and vitamin D often causes such a picture.
You need to consult a gynecologist to know exact cause.
If your sexual life is satisfactory to both partners, please do not worry about it.