I already gave you my advice, doesn't seem to make any difference to you.
Just be aware that while on finasteride you are depriving your dick of DHT, 5AR-II activity, and nitric oxide. All of that is crucial to maintain erections, and sensitivity. Tons of studies out there corroborate this.
If you don't want to deal with this crap, either get your bloodtests to see what's going on, or just quit. But don't keep complaining if yer just gonna continue with it, yer just gonna continue to have side effects.
BTW I also had the decreased sensitivity that began within 3 days of starting finasteride -- never got better, even after quitting. My dick and balls are basically numb, feel like rubber.
Try taking finasteride once a week and see if that makes any diff, get bloodtests, or quit. Those are your options. Or, pop v**** everytime you wanna have sex.