hi. ive been playing for about 4 months on and off. im great with chords and strumming, but right now im learning norwegian wood by the beatles, and im really struggling with strumming the right strings.

for example, when im supposed to only hit the g and b strings, i hit d and g instead.

how can i increase my accuracy so that i can hit the correct strings?

ive never been frustrated when playing, and now i want to throw my guitar. hahaha. thanks for reading.
You may find it easier to simply mute the strings you do not want to ring out with your left hand. That is not to say you should mute all of them and still strum all six (although you can if you're looking for that sound) but in your example you could mute the D and high E, and perhaps A even, so that they don't ring out due to lack of accuracy.
Your accuracy in strumming select strings will increase the more you play, eventually you wont have as much need to mute strings and you can choose to mute or strum accurately depending on the sound you want.
You can look at some alternate picking/string skipping exercises. Really getting that control over your right hand will take some time, however.
Quote by jpnyc
You are what they call a “rhythm guitarist”. While it's not as glamorous as playing lead you can still get laid. Especially if you can sing and play.

Beer is the solutions to the world's problems.

Scales. Slow, accurate practice of scales, especially patterns involving larger interval gaps.
Think horizontal instead of vertical.
I would say Norwegian Wood is a bit out of your league at four months, TBH. But to increase accuracy, instead of looking at your left hand, look at your right. Gets simple after a bit.