Postpartum Constipation

My LO is now 3 months old. I've been having trouble pooping every 2 weeks since giving birth. The doctor gave me a prescription of suppositories and Lactulose to soften the poo. I was practiced this as a remedy for 7 days which worked fine. But as soon as the days were up, I had the problem again of not having an urge to poop for 3 days then when I need to, it's like I'm pooping shards of glass. I went back to the doctor who examined me and said I had an anal year because of forcing myself to poo and I told her that I don't force myself, I poo only when I have an urge. She prescribed a gel-like stool softener that I drink with water everyday. I have to drink one a day. I'm frightened that this will be the rest of my life. Is anyone else experiencing this problem since giving birth?