advice on traumatic experience

this past winter, i was playing indoor softball and had a line drive hit at my head while playing at a close distance. luckily, i was wearing a face mask and after going through tests and spending hours at the hospital, all i walked away with was a concussion that lasted a few weeks. i havent had to play since then, but i have a scrimmage coming up this week and im terrified. i wouldnt say i necessarily have ptsd, but i have had nightmares about it reoccurring and thinking about playing again makes me feel sick. its really hard to explain the feeling but it makes me miserable, and nobody around me understands. they say to just “forget about it” or “loosen up and play”, but its not that easy for me. im afraid im gonna get there to play in the scrimmage and im either gonna freeze or break down. i dont know what to do, i just need help or advice, honestly anything will help me at this point. am i overreacting or is this really a big deal?