Corona, when I picked up the trumpet again, in SPITE of playing the euph regularly, I sounded awful. I was even blowing C within the staff flat! Don't worry that you can't play a full scale yet. I'm a couple of months into my comeback and every day gets easier. While a lot of my focus has been on embouchure development and breath control, I'm making forays above the staff with greater frequency and comfort as time goes by... You'll get there!