Ford Focus 1.8 Zetec 215 thousand on the clock?

I have a ford focus with 215k on the clock on the weekend i done a 250 mile journey from Plymouth to canterbury, and as i got there there was no oil in tank, after topping up before i left plymouth so topped it up there got home and there was no oil in the tank again should it be burning that much oil, and would anyone suggest me putting thicker oil in? As im doing the journey again this weekend?