Ganbatte.
It can be a bit hard before you figure it out. Especially castle battles. First game runs have some mechanics to help you catch up if you fall too far behind, so you'll probably manage to recover... eventually.
I restarted already I got attacked by 4 generals after that they got some zombie plague and demon guy that killed my one commander every turn I think didn't trigger any helping mechanic.
It looks to me that you weren't aggressive enough in the beginning. The Hara House and Ashikaga House are somewhat easy and should be your first targets when starting out. The fact that they are still standing this late in the game means that you've probably been paying off Ashikaga not to attack you. That's a mistake. On your next go around, take them out first, followed by the Iga House.
For generals, you'll find some valuable early commanders by taking out the Ashikaga (Isoroku) and Tokugawa houses (Senhime...best gal). Also, you want to work your way to Uesugi territory for Kenshin and Naoe Ai, but doing so by slicing your way through Texas can be more trouble than it's worth since other countries are induced into war against you. It may be better to go through the Miko Institute and also claim Natori as a commander. Use your satisfaction bonuses to call in the six foreign commanders. They are worth it. Finally, take a look at your prisoners. If you get lucky, you may have captured Ikkyuu from Ashikaga House or one of the furries from Tokugawa House. Another honorable mention for the Power Ranger ninjas from Iga House who are decent early commanders. Even among the non-story related commanders you'll occasionally find some great generals among the prisoners. In the early game it's worthwhile to hire one or two defensive ashigaru units if you are short of some for your armies. If you run out of command points, fire some of your more worthless early commanders or improve the national power of some of your territories. Good luck on your second go around.