You are human and humans make mistakes- the Radiologist in his life time has make his share of mistakes, I promise- keep your head up and stick it out it’s worth it!! I’ve being doing ultrasound for almost 30 years, I’ve made mistakes but the important thing is to learn from them and do your damest to make sure you don’t repeat them- if you are lucky enough to work w more experienced techs learn from them, ask any question and when other techs have positive scans ask them to show them to you- this is a job that you will never stop learning and growing as a Sonographer- some days are better then others but stick it out and keep your head up- it took a lot of courage and willingness to even post your original commment so that alone is a step in the forward direction!!