I haven't done much hiking but if I ever did it again I'd leave the tent at home. 3-5kgs in a reasonable price range, its not worth it for the comfort in my opinion. Just get a small tarp and some rope - find some sticks to hold it up, or just wrap the tarp around you. It usually only needs to keep the dew off.
If your hiking somewhere you KNOW there's going to be fairly clean streams/rivers, take puri tabs, and less bottled water.
If your allowed to have fires, don't bother with a stove. There's another 1-2kg's. Just take 1 or 2 light pans. Take food that's going to give you more energy for less weight. So canned foods not usually as good as it seems. Pasta's good, light, and easy to cook. And the packaging is easier to take back out.
If the packs uncomfortable for only 3-5hrs I'd seriously look at another pack, but unfortunately you get what you pay for. I bought a ~$120 pack when I did the south coast walk, ~16kgs of gear and had bruises down my shoulders and lower back after 2 days
But that was hiking for at least 6hrs each day.
Depending on where your going, if it was summer, you might even think about leaving the sleeping bag at home.
And when your packing, don't think of what you might need, think of what you can do without, and what you absolutely can't. Then pack accordingly.