At a Loss ...

I really don’t know what to do. I’ve tried talking to my husband nicely and numerous times but nothing changes or helps. For probably the past 6-8 months he’s acted like the kids and I are a burden, and acts like anything I ask him to do/help with is a huge task and complains about it. We have 5 kids, but only 2 are his (the other 3 are from my previous marriage) and I know sometimes they can be annoying and loud and stressful but it’s getting to the point that he’s really irritating me and hurting their feelings a lot because he’s so snappy and hateful. I’ve tried asking him if he’s stressed and what’s wrong but he just says “nothing,” “the kids are stressing me,” “I hate my job.” Those are the only things I’ve gotten out of him. We were together 3 years before we got married and he was a completely different person. My kids adored him and he had us all laughing all the time, he was so attentive and I didn’t hardly ever have to ask him for help because he just did things on his own without me asking. He would help me clean, bathe kids, do homework, dishes, he did a lot for and with us. Now, if I ask for his help with anything at all, he sometimes will do it but not without an eye roll, aggravated huff, and smart comment. Like “I go to work for you that’s all I have to do” or “Why are you so needy?” It’s making me mad because 2 of the kids are HIS we made together and the other 3 he knew about before he even married me so why act like this now? I’ve been doing everything on my own for the past month because he refuses to do anything, so it’s like he’s not even here. I feel like a single mom and I’m not single. If I’m doing homework with my older 2 I’ll ask him “hey will you go change so and so please he needs a diaper.” Or “Will you take that trash out for me while I’m bathing them?” “Will you go get me some wipes so I can change this one?” And it’s always a huge deal and they’re not even big tasks. I’m just asking for a lending hand I mean he is their father. I’m to the point I’d like to be alone since I feel like I’m in this alone anyway. But he refuses to leave the house which is mine anyway and I’m not loading up 5 kids from their home when it would be much easier for him to go somewhere for a few days. I just don’t know what to do or say anymore.