salam 3lekum
your feelings are so normal don't worry it can be , all you need is time till tou get used
you think you won't be able to understand afer along gap or you won't be able to continue understanding from where you left after the course but all of that is normal and you can remove this feeling after a really short time after continuing again .. yani from an experince i'm saying that .. i took a gap year after high school for ex and i learned physics on grade 11 but despite this i discovered after attending university i still remember not just the material but also how to solve physics problems even without taking the classes ! which i didn't think for a moment i will be able to understand/remember anything from the subject after three years from the last time i learned phyiscs !
yani sister all you need to do is to believe in your abilities .. and think positively .. cuz you can be whatever you think you can to be ,,and you can do whatever you think you can to do ..
maybe your first step to remove this feeling is to take a deep glance to the material you leanred in the course to be in the air again .. and step by step you can handle understaning the rest of the course ..
and another thing: do you find yourself having a lot of trouble studying
ofcourse , but we have to keep ourself motivated . else we'll do nothing ..
wish for you the best ;)
salam