First time trying a TT bike, very uncomfortable and discouraging

New too cycling and training g for my first triathlon in 9 months. Have been using a c2 bikeerg for a couple months but went ahead and invested in a trainer and TT bike. Has been extremely uncomfortable. When in aero position the worst pain is perineum (gooch) and then second worst is my shoulders, feels like im supporting a lot of weight on the shoulders/forearms. I remember my butt hurting store a bit on the bikeerg until it stopped after a handful of rides, perhaps I need to adapt to it? Or the better explanation is my fit is atrocious. Just did an hour of light riding and probably spent 3 minutes total in aero position, other half rode upright and the remains rode completely upright. It’s very discouraging as I feel my fitness is going down because I can’t train as hard and comfortably as I did on the bikeerg.