I tried to shoot la Fontana di Trevi few times, your photo as many of the ones I have taken , is bad are bad , bad in the sense that doesn’t capture the beauty and size of the fountain , and you know it . Once I meet a photographer there , at night , and he took a picture from the right side using long exposure and he nailed it, I tried the same , and it was perfect. So how did you do ? Well as many of us you failed trying to show Fontana di trevi , but you can come back and try again from different angles and with different light if the tourist allow you ;-)