Rachb, straining may cause piles. So please go to the doctor and get a complete regime for making over your colon and or rectum so they empty easily.
Possibly the doctor will not have time to do more than prescribe a laxative. If so please consult the practice nurse, or practice dietician.
It's not good to rely on suppositories every day, but when the bottom end is blocked the sort of suppository that softens the blockage is the most gentle sort. If unsure do please ask the pharmacist about which suppository. They usually have a private room for a consultation.
Ideally someone would give you an enema as that would not cause problem or discomfort . But I don't know who who to recommend, unless you can get hold of a private nurse or a practically-minded friend to do it, after you go home.