Started Smelly Bowel Movement. Feels Uncomfortable Around Anus. What Treatment Should Be Done?

Hi i have had this problem for about 15 years,i m too embarrassed to go to my doctor about it,i have a constant smell of poo coming from my anus .When i go to the loo i m on for ages and even then i don t feel like iv e passed all of it,it then takes an age to wipe clean,the smell gets worse after going to empty my bowels,it feels uncomfortable all the time round my anus and i m always in pain down below wether my poo is hard or soft it hurts when trying to get it out.I don t know what to do anymore it s driving me round the bend,i have no friends anymore as i m scared to go out socialising as people have passed comment in the past,please help.