My DS2's tanties have escalated recently also. I have started to try using a calm and gentle voice, sometimes whispering to DS2. No matter how frustrated and cranky I feel! And trust me I feel like my head might explode some days. I have also tried making my responses less negative. Trying not to say no, don't, can't, and then distracting or showing the correct behaviours...so instead of 'DS2, no don't hit your brother', it's 'DS2, you hurt DS1 when you hit him, gentle hands' and we do gentle hands on each other (as in patting or hugs). Instead of 'No you can't have crackers now'; It's 'Lunch time is soon. You can have crackers after lunch, lets go outside!'.
HTH!
Good luck. 2 is a hard age for some kids! Though I never really had terrible 2's with my first two kids! It's tough dealing with someone so unreasonable, and egotisitcal, who doesn't understand or see things from other's POV.