It seems like your reasons for considering dropping science aren't out of lack of "liking" for science. The external reasons are always a factor, i wouldn't be so easy to discount them.
I think (1.) will happen regardless of whether you study science or not won't it? Just don't talk about it or find some way to mitigate it if you can. This reason, whilst shitty, has nothing really to do with studying science in university on a pro/con basis of how it'll benefit you. As for 2, you don't necessarily *need* to do an area related to engineering, of course you can if you want to though and in the end it is up to you.
I think you probably have to be honest with yourself over why you question your ability to get good scores in science and engineering at the same time. It seems you love astronomy deeply, lack of interest is a major factor in not succeeding in uni subjects. So, why do you feel you cant succeed then? Dispite the minor hiccup this semester, how have you gone overall? If you have went well and you love it, i see no reason to stop taking it really.
Indeed, as b^3, it can provide a well deserved break. It's the same reason almost no one takes a law degree alone (instead combining it with arts, science, etc). It's because it provides a bit of a break and keep either content fresh because you see less of it.