Given that, I'm a little surprised/curious you have a fiancée, but that's neither here nor there.

I'm a little unclear on the medication timeline. Cymbalta is an SNRI, and as such has the potential for sexual dysfunction.
If this is the cause/reason, something you might look into trying is L-tryptophan—a precursor to serotonin. L-tryptophan is not an aphrodisiac; it is an amino acid whose production is reduced by taking antidepressants. Sometimes it can help restore brain chemistry balance after antidepressants have been stopped. Consult your doctor about this.

DO NOT take L-tryptophan if you are taking any antidepressants or other medications that increase production or decrease re-uptake of serotonin, as this can lead to a potentially life-threatening condition called serotonin syndrome.

I'm not so sure he is—or will be over time.

IMO, a more likely candidate is the molestation.

childhood molestation effects in adulthood

That would best be addressed by a professional. This is nothing to be ashamed of or be embarrassed about; you were/are the victim here—not the perpetrator. You are definitely not alone, and there are support groups for/specifically addressing those kinds of issues.

childhood molestation support

Doc