Anger and emotional reactivity - untreated partner

Hi Everyone 

I am new to this forum and looking for any advise as I'm alone with all this. I feel quite lonely and have become low in mood and trapped with a load of bottled up frustration,  about my relationship.  I'm totally confused about the way forward and whether I can even see a future a man who I have sent with fir 16 years .  My partner is suspected adhd but this does not  rule out comorbid conditions also like oppositional defiant disorder  and personality disorders like he mental health assessor once indicated. .  He has waited 3 years for a diagnosis for adhd and had a final video assessment around 2 months ago. still nothing back from the assessment centre.  He is 56 and I am 41, 15 years ago I met him.  He seemed chilled out some days  but others terribly irritable and had intensely negative feelings if he was triggered he was volatile. I  had no clue to begin with why this was.  I find 16 years in, I am becoming resentful and low most days as I simply can't cope with his negative outbursts to anything that sets him off, the cycle of obsessive ideas and complaints and being overlooked has become too much in the last few months .  My partner is a strange mix, he is extremely clingy and hates being alone with his own thoughts but he can be kind, sensitive , genius and the Byers tiny bit Intensely codependent on me  too . He wants to be with me ALL the time and resents I have to work full time and currently am choosing to work overtime.    I usually keep quiet and bite my lip when he rants but he  just seems so down on life which is exhausting and notices the negative people in life  .  He always states it's the way I am and you just have to deal with it!  He usually has bad road rage or vents a lot to the TV holds my ranting conversations at night? . Not to the extent he would get out the car and hit someone with Rd rage, just really bad language at absolutely anyone that's slow or makes the wrong  move etc. He is hugely impatient towards anyone especially me. So I am always slightly anxious about doing things quick enough. I am recognised  how I'm loosing me and just trying to curb myself so he's not irritated most of the time!
6 months ago he stopped using cannabis I was proud of him for doing this but in the back of my mind I knew all hell would break loose as selfishly weed seemed to calm his mind and dampen his anger towards things he spotted that triggered him like people's bad driving, people getting in his way , moving to slow, me doing saying the wrong thing and his dreadful impatience .  His symptoms of hyper focus, reactivity, moodiness , no sleep and constant spiralling  ideas and complaining at everything and anything take it's toll on me.  My partner can't hold down a job because of his reactions and outbursts to Management in places of work. I'm the earner and am working too hard and doing over time every weekend now  to compensate  but to top it off this makes him feel like he can't be a provider and not a man.   He's not interested in sex without the weed anymore he says he's depressed so it's an unspoken taboo .  I nolonger feel like making love to someone that seems to me so irritable, it saps my energy.  To top it off he looks at porn ALOT bordering on obsessional I believe? So I feel even more like there is a lack of connection .  I tried to speak about this subject recently and ask him if the there was anything we could do to change things? He just became annoyed and stated because I worked a half day on a Saturday there was no longer time to think about sex and I was always too tired in the week so he had to except this.
The reality is at times at the weekend when I do try to initiate romance he's not into it  live making at the weekend he is nolonger driven .  He stops up until 3am every night doing whatever  and then sleeps in till 12pm or 1 pm everyday of the week.  He says there is no reason for him to get up at the weekend as I work till mid day so he then blames his lack of motivation to me because I'm working?? . Everything always rests on my shoulders never his which is why I now feel very hurt and extremely  indifferent about him.  He does have money and an inheritance so he is looking to set a business up but he keeps going from one idea to the next and never settles at anything?? He can be ve our outs to an extent although does not wish to spend his inheritance on bills really. So therefore I'm working more so that I have a safety net for me! 

I I'm so tired emotionally .  I just want to leave in one sense but he's in another when he's calm and upbeat around 20% of the week (if I'm lucky) he's the man I love again.  I really don't know away forward I can't cope with his awful irritability and obsessiveness and problems trigger him greatly and we just end up rowing as he feels personally attacked.   Then I  retreat to being with my own thoughts for weeks biting my lip and my lowness has turned to depression? 

as mentioned my partner has never received any treatment since a little boy. Can anyway advise f there may be hope for us with treatment? I am drained and feel empty .