Effexor (this drug's brand name in the US) can cause more than a loss of libido. I have a male friend who is bipolar towards the depressive side; he reported having "unhedonistic ejaculation" with his wife:

en.wikipedia.org/wiki/Anhedonia‎
This condition means that the person will ejaculate with no accompanying sense of pleasure.


Is it common?

Venlafaxine - Wikipedia, the free encyclopedia
Abnormal ejaculation/orgasm - 12% (0%)

12% is a LOT!!!

So you are basically taking a drug that has been known to screw up sexuality big time (!!!) and instead of talking to the psychiatrist about this drug, you are feeling guilty that you might be a lesbian. And, thinking of breaking up.

To that I say: let us start with the simple and straightforward as we hypothesize about the cause of your lack of libido.

What is simpler and more straightforward:

1) You are reacting to a medication that is well known for causing sexual side effects (as Webgoji pointed out, it also causes nightmarish detox if you were to quit, as I have learned from that friend of mine who does not experience joy from orgasms)...

or

2) You are, all of a sudden, a lesbian, even though you have never felt inclined to engage in homosexual relating (interpreting the omission in the OP to mean that you have never felt so inclined).

So, what is the SIMPLER one?

...

And yet, you have not seen a psychiatrist for a long time. And even though your therapist at least wants to obtain psychiatric consultation, the therapist is not motivated by your lack of libido. The therapist is motivated by T's belief that the meds aren't working anymore (we do not know and whether they are is a completely separate issue). So, then I start thinking that perhaps you have not reported lack of libido to the T and that is why the T is clueless. Have you talked to the T about it?