Took first dose of Effexor and not feeling great : Effexor

I’ve taken fluoxetine and sertraline in the past for my depression and never had any side effects that I noticed. Earlier today I took my first dose of venlafaxine/Effexor (XR) and it was a low dose (37.5mg) but I started feeling awful a couple hours after I took it. I haven’t been able to eat anything at all since taking it about 8 hours ago because the nausea and loss of appetite has been so strong. Initially I felt both very sleepy but also had this weird increased hypersensitivity to sound (the bugs outside sounded so loud) so it was very hard to take a nap. I’ve felt very out of it and not myself, and felt like I may have had a high temperature for a few hours. I don’t plan on taking it again so just wondering, how long are the side effects likely to continue for if I’ve only taken one dose ?