Sorry but we only help publicly here on the forum. If getting help with it counts as plagiarism then it makes no difference whether it is on the net or done privately, it is still plagiarism. The only difference is that you don't want your lecturer to catch you!
Actually you haver misunderstood the word plagiarism a little. It means copying someone else's work - which is why your lecturer says that if he/she can find it on the internet then it is plagiarism, assuming that you have copied the information from there. If you just get help with your own original writing that is not plagiarism. IT could be considered cheating though...