For the past four months, I have noticed a decrease in libido to the point that I am not able to complete ejaculation when I masturbate watching pornography. More specifically, my hands shake quite a bit and I do not have enough strength to masturbate and to maintain an erection. In 2009, I was diagnosed with schizo-affective disorder and I currently take Invega Sustenna (234 mg injection), Saphris (10 mg), Ferrous Sulfate (40 mg), and Metforming (1000 mg x 2 Could the problem be neurological?