Leveling a home

I have a 80 yo pier and beam home that needs leveling. I began to notice that the back door in the kitchen was sagging and that the whole kitchen about two feet out from that door was sagging and unlevel. So I bought three bottle jacks, some 4x4's and so on and attempted to do it myself. Ha ha... I can't even hang a photo on the wall straight... I discovered after talking to my mother, who I bought the house from, that at one point there was wood on the ground and it use to have some serious termite damage and most of the wood had been replaced. After crawling around under the entire house the only problem I found, and what I assume is my problem, is a 4x4 beam under the outside wall that is holding the door up. It looks to have recieved serious termite damage and has dropped that side of the house. It does not however currently have any termites in it and the wood surrounding it is not damaged. My problem is I cannot figure out how to replace it and level the house. Do I need to just cut it out and replace it and then level the house? And how do you level the house? I started jacking it up and it made the most aweful noises after about three inches that I thought the house was going to fall apart. It scares the crap out of me but I am a single mother and there is no one else to do it and I certainly cannot afford to pay anyone. I really want to rebuild my kitchen that I tore out but I do not see a point in doing that before I fix this problem. Thanks for any input!

I don't know anythign about replacing the wood (hopefully someone more knowledgeable will chime in), but I have heard a thign or two about jacking a house.

You need to go slow. Three inches at a time is much too fast. Jack it maybe a half inch and wait a bit for everything to settle. By a bit, I mean at least a few days. Jacking up a house is a very slow process. I may be erring on the side of caution with too many days, but take your time.