So very sorry to hear you have lost both your parents at such young ages and in such a short time of one another. I think it is the hardest thing to lose someone so close to you and with the added responsibility of needing to be there for your young brothers, this burden must weigh even more heavily on you. Sadly, loss is such a momentous thing that I found I could never be the same old me again and had to get used to the person losing both my parents has made of me. Some days are harder than others and this time of year is harder than most also.
As many here will say, it's not a matter of getting 'over' it, but more a matter of learning to live with it and accepting that this has changed you and that you will not be the person you were anymore. Time does make it easier as acceptance sinks in, but the loss will always be part of you, but then so will all your happy memories of being together and this can help make you stronger. I find we carry those we have lost with us daily in our heart and much as we miss them, have to slowly move forwards, one day or one moment at a time. I am sure you will still hear the words of advice your pareents might have given you in your head when you need it.
Your world is changed and it can't change back, but you can move forward and learn how to be the new you on that road. As others have already said, we understand here just what you and your brothers are going through. Be kind to yourself and to eachother. Find the little things to do do that help you along it. Walking in the park, or having flowers around, looking at photos - whatever helps you. Maybe when you are all strong enough, make time to do something to remember your mum and dad together and celebrate the time you all had with them.
You can't shut out the loss, but you can make this easier on yourself by listening to your own needs and doing what helps you feel better, one step at a time.
Wishing you all well.