What you are having is premature ejaculation. Premature ejaculation(PE) is not uncommon and depends on multiple factors , the most common being psychological factors like stress , anxiety, depression which can be due to personal, professional , financial and other social issues which one deals with each day. The other factors that potentially lead to PE can be organic like diabetes, hypertension, hormonal imbalance, trauma etc. Based on your description, it seems likely to be more of a stress and anxiety issue and try to be little patient and realistic in terms of performance expectation. A good psychological and physical health will help you most.
I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
Hi why dont you have a break from sex once and while you will feel better for doing so. I am sure your bf is faithful to you relax lol Take care .....Bob