This drug has a very checkered past. If you haven't already, you should read Wiki's summary:http://en.wikipedia.org/wiki/Reboxetine
If it works for you, then that's great of course - everyone is different - but it does not appear to be better than placebo and it also appears that Pfizer may have - shock! - doctored the data somewhat.
I have not found any references that say that this can lead to sexual dysfunction, but all the drugs that touch your neurotransmitters can do that. So one of the first places I would look is this medication. Just do a search on this board for the various antidepressants and you'll see many stories of how these have negatively impacted the sex life of many posters.
By the way, I'm not saying you shouldn't take the drug as severe depression is something to be taken seriously and "any port in a storm" so to speak, but "eyes wide open" as they say.
Now jumping to your testosterone. First of all, your testosterone is on the low side and testosterone in the 300's often really affects the male brain. Again, there are many guys on this board who can tell you that. Now some men in the 300's seem to do okay and are symptom free, but many, many are not. Almost every guy writing into this board with classic low T symptoms will be in the 200's and 300's.
See this link for examples of "normal" testosterone levels and you can see that you are well below the average:http://www.peaktestosterone.com/Testosterone_Levels_Male
I don't know if you are in the U.S., but you can almost always find a doc that will treat you if you are the 300's with the symptoms of low testosterone. Of course, whether or not you go on HRT (testosterone therapy) is a personal decision between you and your doctor.
Here are some VERY important points:
1. If you get your testosterone back up to more youthful levels - around 600 ng/dl - you will likely notice an improvement in mood. Testosterone has a huge impact on the brain and low testosterone is associated with mood disorders and depression - something I cover in my book as you may know. Again, that's something to discuss with you doctor, as he knows your medical history, etc.
2. Again, hopefully you read this in my book, but low testosterone raised insulin levels and is associated with diabetes, Metabolic Syndrome and insulin resistance. PM me and I'll send you a copy if you don't have one by the way.
3. I am not suggesting that depression can be solved with simple fixes. However, don't discount the very significant effect that lifestyle changes can make to your depression. When you are clinically depressed, you do not feel like doing anything, but that is the absolute worst thing you can do and let me explain why:
--Depression is associated with various nutritional deficiencies.
--Depression is associated with low omega-3's
--Depression is associated with being sedentary
I'm not sure why, but often doctors do not even mention this fact to their patients. So check this link out and see if any of it might apply and then discuss with your doctor:http://www.peaktestosterone.com/Depression_Cures
This link may also be of interest:http://www.peaktestosterone.com/Depression_Erectile_Dysfunction
CAUTION: Discuss with your doctor before doing any change as he is supposed to be the expert in drug interactions, etc.