Percocet 5/325 and tolerance

I have been taking percocet for pain and it is prescribed for me to take 1 or 2 every 6 hours not to exceed 8 per day. However, since the effects of 1 or 2 do not last 6 hours I take 1 every 3 hours at the most. Sometimes I skip a dose if I am managing pain without them. At first, they seemed powerful and made my head feel foggy. I only took them at night to help sleep with pain. Since taking them again, I have developed a tolerance very quickly. I need to take more to sustain pain relief, but I do not have too many unpleasant side effects. They help me sleep and manage pain, but I get extremely constipated, have strange dreams and get impatient and emotional pretty easy -- but the emotional impatience is also a side effect of extreme pain.