Antidepressants and fertility

Hi folks!

Looking for advice, my partner and I have a gorgeous little girl of 18 months now. When she was concieved my partner was on Mirtazapine 15mg, he now has too high a tolerance it does not work so his meds were changed. He has since went through further evaluations and was prescribed citalopram, after we both read through the side effects we chose to reject this medication due to potential birth defects (due to our ages we were informed that potential side effects were more probable because of this) we both want another child within a year or two and wanted to reduce the potential for birth defects, after speaking to partners psychiatrist he was prescribed duloxetine 60mg which is described as being for men with fertility concerns but it's been about a month of him being on it and he can get "firm" but can't finish. My birth control runs out in a week and we were hoping to start right away but he cannot 'finish' at all! No matter what I do, no matter what sexual acts I 'preform' he cannot get over the finish line. After going through the side effects we realise it is a common side effect of his meds but we were not informed of this. The unfortunate part is the meds are actually working for him, can anyone recommend a medication he can be on until we get pregnant and can go back to his old meds after?

Sex is not a bit deal for us, I can sort myself out when I feel the need and since starting the meds the "need' has not struck too hard our relationship is extremely fulfilling otherwise and sex was never a grounding block for us but at least two babies have been our goal from the start, we both really don't need gratification we both just want to perform enough to make another kid, we want our girl tobajbw a sibling and both feel it would make our family complete.

We are in Scotland if it helps, please can someone recommend an AD that will work either long term or until we get pregnant? I'm happy with one baby but he wants a few and I am writing this because I am happy to give him as many as he wants but we are struggling with the baby making process because of his meds.

Please just give us some advise, what worked for you?