handsomeone wrote "It's been over 2 days and it shows the post has been successfully posted, but in fact it doesn't show up on my page. " I suppose "it" means the bot was showing a post was made (or at least attempted)?
How did you first notice that you weren't able to post images? Were you posting images by a bot? Have you noticed any error messages or issues from the bot or from Instagram recently? If you are posting using a bot that's common and works for most people but you might have gotten your account flagged by doing that (probably just temporary). You might try posting an image and caption, etc, by a phone / tablet / mobile app and see if that works, and verifying the post was made by viewing your account while logged into a different account on an app or browers or while not logged into at all on a web browser.
If you are able to post from an Instagram app ok and the issue with the bot persists beyond a few days you may want to contact the bot company and let them know of the issue, it may be a change on Instagram's side and not anything wrong with your account. Instagram frequently makes changes to its code which bot companies issue updates to work around and if it's an issue you notice only from the bot that may be what's happening here.