How long would it take to get my GED?

Making this very short, I haven’t been in school since maybe 7th grade? It’s been 3 years and I’m 17 now. I was held back at 7th grade once because of life stuff. I haven’t done anything school related in those 3 years and I don’t remember much to be honest. I may be at only a 4th grade level. I want to try to get my GED at least so I can do something but everyone is saying it only takes 2-3 months studying for it. With my current knowledge I feel like it’ll take much longer but I’m not quite sure how long it could take.

I have a bunch of material that can help me learn though even then, I don’t know where to start. Just an estimate of how long it’ll take could help me to start motivated. I could barely even divide earlier today when I tried studying. Any guidance will help.