Hi M.,
First, you are not alone w/the dealing w/fighting/fussing w/your children! I think most or all families have that at one time or another, or many!
Question: Is there any way that your boys could each have their own rooms by chance? That may not be possible, and am not saying that is or would be the 'cure' for their fighting, but it might help as they may just need some of their 'own space.' Esp. for the older one, which will become more crucial with time.
Lastly, children fight! Or fuss! It is within their nature even on the best of days. Things can be going along wonderful, then, Boom~what happened?! This is not to say it is acceptable or that you should have to endure it all the time, 24 hours a day, nonstop and that there should not be consequences, because I think there definitely should. Afterall, when these young fellas get older, what behaviour are they gonna look back to or resort to when they need to work something out at school, or work, to fight about it verbally or physically? I think not. They would not get very far!
I would suggest a couple of things...first, find out the problem and hear them both out...then, seperate them both. If one is obviously guilty, say of hitting his brother, then he gets the punishment...but the seperation needs to happen at least for a little while. If things are at a height even you feel you can't handle or it seems overwhelming, as crazy as this sounds, 'make' them go outside (w/you watching) and run around say for instance, the front yard, twice a piece..anything, to get their attention elsewhere and the anger watered down a bit...enough that they are talkable...this will only work while they are young though...but if you can do it, start w/that. Say, 'okay, boys, let's run. Or, you gotta go run.' Then when they come in, I promise you they'll be better adjusted and situated to hearing 'you,' Mom, than before. I'd address the problem, make them apologize, then have them both 'still' spend time apart if you feel it is needed and the mood/behaviour is not resolved, then they can come back together. You can always try having them (well, only your 7 yr. old at this point) to 'write' sentences. I will not fight. 25 times. It will drive the point home. And think of something comparable that your little one would have to do, maybe not 25 times, but you know what I mean, so it would be fair. Later at night, too, hug them and say how it makes you feel to see and hear them fight. When they are calming down for bed, they will be much more susceptible to hearing you, than any other time. They may at this time be more open to you and ask them, how can I help it that you and your brother won't fight so much? Tell them to look and talk to each other, even if you have to provide the words for them, that 'they are going to make more of an effort to use their words and not their hands, for instance, when conflict arises.' I hope this helps! Let me know. I have three kids, ages 2, 6, and 9; two boys, one girl...AND my husband is gone a lot too and works nightshift, and I have NO family up here, so it is only me! :) Best of Wishes. *Don't forget too, to reward them for good behaviour...like, 'Okay, pizza Friday night if no fighting for two/three days straight, or something like that.' Make it realistic enough that they can actually do it.