Iris,
I'm now about 4 weeks into my exercise plan. But, a month ago I was exactly the same as you, I 'wanted' to exercise, but still never quite got round to it.
The only way I motivated myself to start (and now I can't imagine stopping!) was because I had a goal of moving back to the UK, which is now 5 weeks away. Can you set yourself a goal of something something up you want to be fitter/thinner/healthier for?
I'm also far more motivated because my housemate also started working out at a similar time to me. Even though we workout independently (she's WAY fitter than me!) because I know she'll be going to gym, it means I have to get off my arse n do something too. So maybe if poss an exercise buddy would help with your accountability? If not an actual one, you could join a thread on here where you log your daily exercise, and that might spur you on to workout
I hope you find the motivation soon, the initial start up is wayyyyy harder than anything else