What is wrong with me

I don't know what is wrong with me....

I have moments in my life like right now, where I get so upset

I have a very stressful job, I don't mind my job when I'm doing it but being self employed is so stressful on my mind and then having to work physically on top of all.
My partner is very supportive. He tries everything to make me feel comfortable but I have a go at him at little things.... I could already cry when he doesn't say hello to me properly when I come home or when he says something innocent, I will take it straight away the wrong way. I was looking for a simple dish and when I couldn't find it, I ended up throwing everything out of the kitchen cupboards and just broke down in tears. I can't even explain my frustration or sadness.
There are days where I like my job, I come home, happy times. Then there is days where I already wake up, and I cry because my partner said for instance that he had a dream that I cheated on him. I get so upset that he dreams something like that, my mind is digging into that little bit of detail 'am I that terrible that he dreams of me this way?'
It's like everything he says, I put on the scale, and try to make it be negative and then get upset that it's negative and on the end I don't even know what this was about?

It never happens with friends, I generally have a short fuse when I work lots but why is it so important to me that my other half only thinks best of me and that I get so offended if he says the slightest thing and loose my absolute shit about it?

I don't understand myself and it's like as if someone flicks a switch and all I feel like is screaming and crying and no one can get me out of that moment.

I want this to stop. I became a moody person that is super sensitive and I feel sorry for my partner.

Also in the past year I became that person that finds a fault in every person, I complain all the time what I can't stand about a certain someone and everyone just pisses me off with their selfish behaviour. But why can't I accept anyone for what they are, I'm an idiot myself with all these issues that have been raising for the past year
What is wrong with me