I was in the same situation as Spain. I tried to secure the Iberian peninsula and Western North Africa. I then invaded Italy via Sicily. After Demolishing the Italian powers I was surrounded. France's assassins started butchering all my generals I left in towns behind my front lines. Then they started invading Iberia while the HRE and Hungary started attacking my now depleted armies in Italy. Then Poland (somehow they replaced Egypt

) began assaulting my African regions. Then was the most difficult. Somehow a bunch of English armies landed near Lisbon. It took a while, and I lost a lot of land (Only Iberia and a few in North Africa) but now I managed to repel France and England. the HRE and Hungary are now fighting over Italy and Poland is in my cross hairs. Try getting your opponents to fight over regions and get as many Bishops as you can (they help with your relation to the church). Just watch out for those Frenchies, they can be a real pain.