Not sure where to start here, might be a bit rambly, sorry! I have two DCs 3.6 and 2.3. I'm a SAHM, and DC1 is in preschool usually for 3 sessions a week, and I have DC2 at home with me. I've been really looking forward to the summer holidays, but 2 weeks in, I am ready to sell my children and emigrate!
I love them both to bits, but right now they are so full-on. They fight and whinge so much, and the last few days I've found that I've totally lost my rag with both of them, becoming a horrible, shouty mum, and I've had to walk away several times shaking with rage because I'm losing the plot. I think I've shouted so much that I'm reluctant to open the windows because my neighbour is around during the day and I don't want her to hear me shouting
She must think my DCs are so unfortunate to have a mum like me.
We get out LOADS and do lots of fun things together, plus I chuck them out in the garden as much as possible so they are 'exercised', but sometimes I need to stay at home and be able to get on with a few things and they make it SO hard for me to do this, even the most basic of housework/emails/phone calls. I spend a lot of time playing/reading with them, but DC1 especially always wants more, and to play with him ALL the time.
I never wanted to be the person who dreads the holidays, but I'm turning out like this.
DC1 has suddenly gone from being very laid-back and easy-going, to becoming a lot more boisterous and pushes/shoves/head locks DC2, and it's driving me mad. DC2 pinches and bites her brother in retaliation, and this morning bit a hole in his tshirt
DC1 has also started having tantrums which he never had at 2. I'm finding 3 so much harder than 2! They have always been very chatty/verbal for their ages, and I often find myself negotiating with even DC2, before I think "why the hell am I letting a just 2 year old dictate what I do?" It's just exhausting, and by the time they go to bed I'm done for and so bloody tired. The argue with each other so much, but whilst they might have the language, they don't have the maturity to actually end any argument well!
Is this just a phase and the perils of having two so close together in age? My siblings were much older than me so I never had anyone fighting me for toys/attention so this is all new to me. I always wanted 3 or 4 children, but I know I couldn't cope, which makes me feel like a massive failure. Especially when we actually get quite a lot of help from GPs.
There haven't been any big changes in our house, and DP is really hands on, so I don't know why it's suddenly like this. Is it normal? DC1 seems quite sad sometimes, and scared of my shouting, which makes me feel awful. I'm worried I'm damaging his self-esteem by shouting so much. 
I'm not depressed and have loads to be thankful for, but definitely feel hugely stressed and on the edge- I could burst into tears at any moment and the rage just comes out of nowhere.
Any tips for staying sane and not shouting? Feel like I'm losing the plot slightly!