I was diagnosed with ADHD in my 40's, am now medicated and honestly it has made such a difference to me. I made my way through life always trying my best, often never succeeding at anything and being told I just had to try harder. It's soul destroying when all you do is try try try, only to be told it's not good enough and to try even harder - especially when you see others trying half as much and succeeding with their dreams.
My son is 11 and I am sure he has ADHD and possibly ASD. Long story short - my husband is extremely dismissive of me even remotely suggesting this and I am yelled at and threatened and told he doesn't and that he's nothing like me. He will not allow me to pursue a diagnosis for the time being. But my son has issues and they're impacting our whole family - me for one as I find his actions very stressful. Husband just brushes them off as normal childhood behaviour and makes me feel crazy for questioning it.
I feel my son is about 2-3yrs less in maturity that his actual age. He has a very kind heart, but is an anxious boy. He doesn't like to be left alone, is often still comfortable to have us come and sit with him in the bathroom for a chat while he has his shower or asks us to accompany him to a public restroom and sometimes will only come in the ladies with me instead of using the mens. Sometimes he is totally fine though and will use the men's and be quite independent.
He is obsessive about song lyrics / phrases. Will find one that he thinks is catchy and will repeat it over and over again to the point I want to scream or strangle him. I ask him 100 times a day to stop. He may or may not. If he does it will only be for a short amount of time before he starts again and I get angry and then he'll claim he didn't know or that nobody told him. This also happens with clapping and thumping on sofas, chairs, beds, etc. 
Everything revolves around poop, pee and general stupid talk. It's got so bad that his little sister copies him so now there are two children laughing and giggling about poopy on your head, and poopy bum or poopy on you. It's just all f-ing poop all the time. This has been going on for 2-3 years and as above, no matter how many times I ask he doesn't stop (for long) until I have to lose my shit and start screaming and then everyone is miserable and I seem terrible. But it is sensory overload for me to the point I feel so overwhelmed I want to cry. I have tried to explain that once perhaps it's funny, twice maybe, but 3,4,5 times it's no longer funny
He asks for things repeatedly despite being told no. Similar to above he just does not understand when to stop. He's constantly asking for the computer / iPad / phone etc even when told no. 5 mins later he will ask again and when we get angry he says he didn't know or he just wants to use them.
He's constantly provoking his sister and winding her up. He will say something mean, call her a dumb name, lie to upset her just to get a rise out of her and make her upset. I'm assuming this is to increase his dopamine levels as ADHD'ers lack dopamine. It's disruptive to the whole family.
Can anyone relate? Does anyone have any tips on how to deal with this behaviour? I'm at my wits end. No punishment so far has seemed to work.