so im playin this series of 4 chords that are on the a,d,g string but when im strumming them i always accidently hit the b string,

i can mute the low e with my thumb, any tips on how to fix this problem? maybe i just suck at strumming and need to get better

since you're only using three fingers you use your pointer finger (fret hand) to mute all the other strings. But really it depends on what chords you're playing... sometimes it doesn't really matter if you hit that b string. If none of those work out, just practice not hitting that b string. But just out of curiosity what chords are you looking to play (just do it in number format from a to g)

the chords are these, and the b string makes it sound bad

e -----------------
b -----------------
g 5--4--0--2-----
d 7--5--2--3-----
a 7--5--2--3-----
e -----------------

and i strum them on an accoustic setting on my electric, (just to clarify im hitting each chord more then once)

Well if you mute the e string, then a strumming space of 4 strings should be enough for you not to hit that B string. If you still hit it, then just practice, ideally you should be able to hit those three strings but I know it can be difficult if you're strumming fast. (anchoring your pinky might help but a lot of people look down upon that practice for some reason)

Personally I've never been a fan of the sound an electric produce's when strumming but I'd say it's just a practice.

One thing you could try is using your pointer finger as though you were going a barre chord then just lifting your finger
enough to mute all the string's below the chord then use your thumb to mute the top string. That's how I would do it in
your case, though you will get a kinda of "muted" sound. Sometime's it sound's great other time's it can sound very bad.