I have taken a few otc products to try to help similar reasons as yourself. I have tried Paravol (got it free) and Ejaculoid. They both helped slightly after a few days but only lasted for a week-10 days or so. I believe it is the Eurycoma Longifolia in it that gives you the libido boost. I think the trib only may help with volume? The stuff in these definitely helps with volume load.
Went to the Dr myself about this. First thing he asked me was, am I depressed. I said yeah, who the hell isn't? Not the thing to say to someone who makes money off prescription anti-depressants. Blood test said I did not have a problem. Low end of test in my age group but not surprised. He wrote me a script for viagra, said cialis was not as good, not as reliable. (?) I keep some viagra around when I feel I need it. Believe me, if you have just a slight problem sometimes, you will not need 100mg, unless you want to kill her. Admittedly, sometimes that maybe required. I break mine in about 1/3.