Metamucil daily is good for this

I have the same issue right after my first child use one table spoon psyllium husk in a warm glass of water or few drops of almond oil in a glass of milk really works

I never had it to that extent, but yes after birth I had problems with constipation. No offence to your Dr, unless they are a trained nutritionist, they aren’t the best advisors diet related. They are taught some things, but see a nutritionist and they might be able to figure what you need to tweak in your diet.
In saying that, my hormones do affect constipation. Usually for me, the week before my period, it doesn’t matter how much I tweak my eating and keep active, I have constipation issues. Then the day my period is at it’s heaviest, I return to normal.
But I would still have a chat to a nutrionist first to see if there is anything they can suggest. Taking a daily laxative could make your problem worse not better. It could create a reliance on laxatives rather than your body just learning to go when it needs to. I would also suggest talking to a physio focused on womens post natal bodies to see if your pelvic floor