Orgasm & Anti-anxiety medication?

Hello,

My girlfriend and I have been together for almost 2 years now and our sex has always been AMAZING. We are 31 years old. However, in the past year and a half she has experienced significant family hardships, so 2-3 months ago she decided to go on an anti-anxiety medication to help relieve her of this stress/anxiety. She also has had always trouble sleeping (very light sleeper), and the anti-anxiety medicine is supposed to help shut her head off so she can sleep. So she started taking it (Zoloft), and we both noticed her anxiety levels decreasing! So great news, however, ever since she started taking this medicine she isn't able to have an orgasm. It's on a very rare occasion that she does and that's after a very long time of stimulating her. Not only is it very difficult to orgasm but her sensitivity is way different. All the "tricks" I used to do no longer feel like they used to for her. She is very much pleasured by everything, it's just the orgasm piece of it that is off. We both find this a bit frustrating, so she went back to the doctors to see if she could try a different medication. The doctor weaned her off of the 50mg Zoloft and put her on 20mg of celexa (she takes the generic brands of these). It is in the same class of drugs, but I guess for some reason the doctor thought it could have a different effect? Well, it didn't. She still has a difficult time climaxing. The doctor told her, if celexa still prevented her from having an orgasm, that she could try something else...something in a different class. Not sure what that would be, but now I am torn. The anti-anxiety medicine is helping for her anxiety but it is making our sex life, a little difficult/frustrating. We actually sometimes start fighting/arguing after sex because of this...this is the last thing either of us what after sex! It is making us want to avoid the whole act altogether. I want to make her feel good, but I also want her anxiety levels controlled. Also, I just want to note the arguments are from her frustration not from me being an asshole (I want to note this so you know I'm not some asshole that yells at his girlfriend for not climaxing), it is mainly her frustrations breaking through. Although I have to admit, that it makes me feel bad sometimes that I'm not pleasing her like I used to.

Has anyone else experienced this? Can you give any advice on what to do? What medication would prevent this issue from happening? Or something we can do to adjust to this, so she is able to achieve orgasm like she used to?

**She used to take the anti-anxiety medicine in the morning, but switched to taking it at night because it made her tired during the day. We usually have sex at night. Does it matter the time of the day she takes it?

Any help is welcomed and please only mature responses.

Thank you.

Elliott