Dad's Depression/moods, Driving me insane!

Ok lads, I got a story for you, I'm going to go as a guest for this one.

I am a male nearing my mid 20's, still living at home with the folks, unfortunately. Can't move out due to the economic situation, I am unemployed, but I recently finished a Jobbridge scheme, so I don't want you seeing me as a scrounger. I hate being unemployed and am doing everything to get myself away from being unemployed.

My Dad was diagnosed with depression about 4/5 years ago. He went on anti depressants and was on them ever since. He had a fairly rough childhood as his dad was an alcoholic and lots of stuff happened while he grew up etc...

While he was on the anti depressants he had been smoking weed on his nights off work and I even caught him smuggling some into work which is downright outrageous I reckon you readers might think.

By what I have read the THC in weed can alter the chemicals in the anti depressants and cause mood swings, lots of arguments went on between him and my mam on and off for years while he was smoking and taking medication. Told him many a time not to and gave him details on what I read but I may as well have been talking to the wall.

Anyway about 8 weeks ago he gave up cigarettes and weed and I was delighted for him, he is on one of those vapour electric cigarette things that is keeping him from lighting up. Everything was fine for a few weeks. Then about 4 weeks ago, we were about to sit down for dinner, and my dad sleeps a lot, he has been taking sleeping tablets for about 10 years as he works nights, he came down from bed at about 4pm and went into the sitting room. he lay down on the couch and watched some tv and closed his eyes, to anyone else in the house we would figure that he was asleep. My mam went in to call him, seen that his eyes were closed and didn't call him and came back into the kitchen and we started to eat.

Dad came in about 10 minutes later, we would have been half way through dinner, and Dad says "Why didn't you call me?" My mam says "Sure you were asleep" My Dad then shouts at her "I was resting my eyes!" then he grabbed his dinner and stomped off into the sitting room. My mam shouted after him "It's called respect, you were working last night I didn't want to wake you" Dad then came back in slapped the plate down off the table and told her to "Stick it up her arse" and stomped back into the living room Yes charming man I know!

What followed was an argument in the living room, mostly consisting of my Dad saying "F**k off" to my mam. My blood was boiling over it at the time, but mam doesn't want me getting in on it, so I and my sister just sit there and listen to it all awkwardly.

I will add I have a girlfriend, she lives a bit away from me, takes a commute to go see her. A few days after the argument I went to see her and went on a short holiday as I had money saved up from the Jobbridge scheme, spent very little money while I was doing it.

After I got back, everything was rosey once again, everybody getting on, the father in fairly good humour, I have another sister who came up home to visit, she is the lucky one that doesn't have to stay here and listen to my father's shyte! She came up anyway and hung out for a weekend and went home on Sunday.

Last night, I was up watching tv and I came down I was peckish and came down to make a sandwich, my sister came down to make a cup of tea also, my mam was in bed reading a book and Dad was in the sitting room, probably sleeping or if awake he would probably be sulking for some reason, I am honestly passed the point of caring, I did feel sorry for him but his moods in general are making me want to split him.

Anyway I came down to make the sandwich and Dad comes into the kitchen and just says in a snarky voice "Why do ye only come down at this time of night?" I will mention that I came down at 1am. He then goes upstairs to mam and just says "Tiiiired?" there was more shouting, didn't hear most of it but Dad came back downstairs and said "I won't be isolated in my own house"

Now you might think my Dad is in the right here, but none of us are isolating him, as far back as I can remember if any of us were in the sitting room, even when we were kids, my dad was always asleep on the couch with some extremely boring RTE1 programme on in the background and if we dared wake him, we'd get a bollocking, so to avoid that we tended to stay in our bedrooms or go outside or whatever. I mean what is the point in spending the evening with family members that won't stay awake?
This method continues, if he wants to spend his whole life not dealing with his issues and would rather be asleep then leave him off, him and his siblings were told to go to counseling many a time and none of them will take action.

The story goes on until as recently as this afternoon, early today we had a heavy shower of rain. My mam has this pet cocatiel, we had him for about 5 years, my mam loves this bird, very tame and lovable pet. Earlier today my Dad hung the cage outside the back door
none of us seen him hanging it outside, my mam went out to bring the cage in and the cage door was wide open and the bird, long gone. The cage door has a very specific knack to opening it, it has a sort of a latch on it, so the bird couldn't have opened it himself. I suspect my Dad opened it and let the bird go on purpose. I think it's a bit of a coincidence that a very petty argument happens last night then the next day my mam's much loved pet goes missing. Honestly am broken hearted over that bird. My mam is having no reaction to it, and I am blisteringly angry over the details of last night, the stuff from a few weeks ago and the possibility that Dad could well have done that on purpose out of spite. He hasn't even been confronted on it yet, he is down in my living room as I write.

I also have another problem, my girlfriend is coming here for a 3 day visit on Thursday, my mam says have her down, but I am terrified my Dad will have another hissyfit and f**k up what I have with the girlfriend, basically I am afraid he will scare her away with his temper. Which will send me over the edge if that happens, she is the first girlfriend in quite some time I should add.

Well what do ye make of that? Any advise to keep me from losing my head?