Why not just sack Rome and be done with the Senate?

I did that with both my Roman campaigns (first one - Scipii and last one before EB - Julii); once my offensives abroad began going well, I simply started building an elite army in Italy and just had them sit in a fort next to Rome until the Civil War began. In the case of my Scipii campaign, I already had the 50 territories so taking Rome meant winning the campaign. As for the Julii campaign, I was smart enough to recruit a second legion to attack the Brutii once the war started as well, and I had to money to bribe away all their forces...

In my case as the Julii, I simply ignored the Scipii completely (they were busy with Egypt) and just conquered the Brutii settlements in Greece with my armies already roaming Europe... but seeing as you're in Egypt for some reason...

Post up a screenshot of your map so we can see what you own.