I'm 47, do have an enlarged prostate, but the only symptom I notice is
frequent urination and a somewhat decreased stream.

About 6 months ago, I started getting some testicular and groin pain, a
dull ache which I attributed to exercise, since I run 3 times a week
and lift weights 3 also. The pain was pretty severe for about 3 weeks
to a month then subsided somewhat but it still persists.

I also had my PSA go from .5 to 1.8 in about two years.

I'm wondering if the PSA rise is related to the groin/testicular pain.
My GP says prostatitis doesn't cause testicular pain.

Any ideas?

Thanks!

I suggest that you request a referral to a urologist and show him or her
the results of your most recent PSA tests and tell him or her your
symptoms. GPs don't know as much about prostate gland problems as
urologists.