Any advice for a struggling mum?

Hi. I'm from a middle cl family and for the past 3 months or so I have been stuggling as a mum and don't know what to do. I have a husband of 9 years and have a 2 and 3 year old kids. My husband works full time and I'm a stay at home mum and it just seems my kids are driving me crazy. I love my kids to bits and I always get told I cuddle and kiss them too much but that is just because I adore them but lately I feel like I've had enough. I have no baby sitters, nor will I leave them with a stranger but my daughter does go to day care one day a week but apart from that I have them 24/7. The kids fight all the time, screeming, crying, nagging, when they say ask me something they ask me 10 times the same question even though I answer them, I take them to the shops for shopping and they touch everything, they don't listen, they constantly play in my kitchen and get into the draws and things seem to get broken all the time. It's just never ending. I do have to admit though my kids are very happy and always use their manners so they arn't being "" it just gets annoying and frustrating. I find myself yelling more, sometimes swearing now, and I feel like just getting the wooden spoon out of the draw and waking them on their bottom. I can't do more daycare because it's to expensive for us. I have no friends anymore because I think they can see the frustration on my face even though when I see people I put on my smile. I just feel exhausted, a failure and I can't see any way out of this rutt. I can't get involved in any activities coz my husband doesn't get home until about 7.30pm and he is also in a band. It's a huge relife when they go to bed each night. What could be wrong with me and how do I fix it?