Pain and straining while pooping. Help.

I have been suffering from this problem from around 5-6 months. On random occasions, my poop becomes very dry, pebble-like and sticky and I have to strain a lot to push it out which causes a lot of pain. It often happens that one day I am suffering from this problem but on the next day I am completely fine, only for it to happen again after a few days. I only eat home cooked food and drink lots of water but it is not helping. I tried taking different kind of medications but they online provided temporary relief. I can't figure out why this is happening because I am strictly keeping track of my water intake and not eating any junk food. Even though the problem is not that serious, it is significantly reducing my quality of life as I often find myself in pain and keep thinking what to do. Please help.