So other people will detail all of the products which can assist you but I am going to recommend some exercises instead. Much of the pain comes first from fatigue of muscles and second from the soft posture that happens after fatigue. Both cause pain, though in different ways, and both can be helped by a few fairly simple exercises.
First, standing on your toes will build your arch. Going up and down, bouncing, slowly raising and lowering, all of these will help train your calves and the support muscles in and around your feet and ankles. This will help stabilise your ankles and that will actually cascade all the way up your legs, back, and even neck. Some people I have worked with have had a reduction in neck pain from simply bounding on their toes when possible.
Second, you need flexibility in your ankles. 6 hours standing is absolute abuse for your joints and they need your support to be OK after that. Squats, especially deep squats, can help with ankle flexibility and strength. Reaching your toes will lengthen the muscles on the back side of your body, all the say up. Getting to having your hands flat on the floor while having your legs straight will improve your back flexibility a lot. Rolling your ankle a little to the side while very very lightly loaded can train the stabiliser muscles for strength at extension.
I would also recommend going barefoot when possible, at home etc, so that your feet can do the work. This will help them train for when you have to wear shoes.
As for the ibuprofen, it is a tool but it has consequences. I would recommend using ice packs and hot water bottles to alternate the temperate of your ankles when they are sore. Spend about 5 minutes with the ice, then 5 with heat, back to ice again if you need. Ibuprofen removes inflammation but you actually need inflammation to heal well, so use it as needed but try to do the temperature methods first if you can. The same goes for paracetamol, use it when it is the best tool but try the other tools first.
Oh, and for your ankles and feet just feeling awful consider a bucket of fairly hot water. Soak your feet for as long as you like. It works really well and is mostly consequence free.