Squeaking noise when accelerating

Hi guys! So, I’m a single mom of three and it’s super important my car functions properly. I’m on a tight budget as it is so any help would be greatly appreciated. So, my car started squeaking loudly when I accelerated. My friend said I needed a new belt, so I got one put on. The noise wasn’t as bad back then either, but this was about six months ago. Now the noise is much worse and louder. Can someone please help me determine exactly what it is? Thanks so much!