hi, a day ago I was constipated and after sitting on the toilet for a while I strained until blood came out of my anus , the blood was bright red and filled up the toilet water . I got lightheaded and felt I was going to faint . I quickly wiped and a lot of bright red blood was on the toilet paper on first couple wipes, after several wipes it was clean. I haven't bled after that , but I can still feel a sharp pain inside my anus. Is this something serious ? Also can this affect my ability to hold in my poop/pee? I ask this because my anus also feels weak