Stop whenever you want, for whatever reason you want, you don't need to justify this to anybody at all. Also, it's not true that it's only beneficial if you do it to a certain age. In fact the benefits are greatest the younger the baby is, and as they get older the less difference it makes. As long as it's working for you and your LO then you can and should continue as long as you want to, but it's also fine to say nope, I'm done, not for me.
On the question if it's about to get better - quite possibly yes, but OTOH I think breastfeeding is easier if you can lean into the fact that it doesn't really always work in a pattern of predictable, discrete "full" feeds at set intervals. It kind of just is that they take milk little and often and it works best if they are in contact with your body a lot of the time, including at night, if you can do that safely. I found this was what worked best for me, it meant I didn't worry about how much they were getting because I knew they would just take more if they needed more, I didn't worry about when the next feed would be needed, I just offered it whenever or let them help themselves. I know this approach won't work for everyone but I found it really freeing.
OTOH I know there are people who make breastfeeding work on more of a scheduled/routine type basis, sort of approaching it like bottle feeding but doing it directly from the breast instead. If you wanted to do it like this, possibly one of the books about how to get babies into a routine would be helpful? I've heard good things about Precious Little Sleep, The Baby Whisperer, Happiest Baby on the Block and <whispers> Gina Ford, although some of these suggestions will be very out of date, I'm sure there will be newer things available now.
Personally I would stick to a book, though, rather than a social media page or an online course.