mummy to Josh - I know exactly how you feel. I would regularly have bad, bad days, when ds just seemed to scream, cry & be so difficult. Inevitably dh would 'phone to say he'd be late home that night. By the time he came home I would be in a right state, and then, after a full day of monster-dom, ds would turn into a laughing, gurgling little bundle of fun.
A tiny bit of me would be relieved that ds was being nice again, and a tiny bit of me would be glad dh was home, but most of me would be fed up, jealous and furious that I'd had a day of torture, and all dh had to do was walk in the door! It wasn't fair!
Then dh & I would have an argument that I thought such shallow thoughts and the day would end miserably!
Anyway, I felt like that for a while, but note it's all in the past tense. I suppose I do have occasional days like that, but they are few & far between (can't remember the last one).
I'm sure you've read somewhere that the 'primary carer' always gets the flack? Which is, unfortunately why Josh plays you up & not dh, or at least not as much. Kids rarely have tantrums other than with primary carer - because they feel secure enough to play you up.
So what's different now?
-Ds is older.
-I am better at dealing with his behaviour.
-Our relationship has deepened (and if Josh is adopted, even if you've been together a year, I guess your relationship is still developing - just like a married couple after a year are very different to after 10 years.
-Our routine has changed & we're more comfortable with our day-to day living - maybe you could work out what you do on a daily basis, see if there's a pattern to easier days?more difficult days. Maybe days you go to the park in the pm are better than days you go in am, or something along those lines?
Do you have regular contact with other parents of similar age children?
Does Josh go to any groups?
Do you have any time on your own?
(When I was particularly stressed out I joined a gym with a creche. I'm not a gym person, but often I would just lie by the pool with a book, and feel more human - it was the only break I had & ds loved it) Now I'm 'established' I've stopped going, but it played an enormous role in keeping my sanity.
I really know how you feel, and it's not nice, and I wish there was something more I could do to help, but I'm confident that at least here in mumsnet, you'll at least have a lot of empathy & support, and it will get easier.