<human>: Give me the gist of the text in a nutshell

Hey r/loseit. First off, I love reading the posts here and this sub reddit is just awesome. Anyways to my problem...

I started my quest to lose weight around 3 and a half weeks ago. I was 240 pounds, and now I'm 215 (lost 25 pounds). I'm 5 feet, 10 inches and 22 years old. My goal is to lose another 30-35 pounds, to get to 180-185 (and around 15% body fat). 

I changed my diet completely. Went from eating out a lot, to eating a lot of greens, protein, grilled chicken, tuna, etc. I kind of know what foods are good for me now. I also dropped all soda and juice and only drink water, green tea, and coffee now. I also joined a gym and since I started, have been going about 5 times a week. I have been told that to lose weight, cardio is what I should focus on. When I'm at the gym, I do 45-60 minutes of cardio. I will use the bike or the elliptical (mostly elliptical). 

So 5 days ago, I weight myself at 215. Today, I am 216 (actually gained a pound). It was a really bad feeling when I saw that. I'm not sure why it looks like I'm not changing anymore. The first few weeks I was losing weight quickly and it seemed like everyday I was down a pound or two. Now for the last week almost, I haven't lost anything and it has been discouraging. 

I am not going to stop, of course. But I want to know what I'm doing wrong. Should I continue doing the 45-60 minutes of cardio every time at the gym, or should I change my workout? Is there anything in my diet I should change? 

A friend of mine said that after a while your body gets used to what you are doing. It expects you to do that hour of cardio and eat these healthy foods. He said you need to "shock" the body and change things. This didn't make much sense to me, but I'd like to hear what this more well informed community has to say. Thanks, and appreciate all kinds of help!
<bot>: Started 3.5 weeks ago and went from 240-215. Have been at 215 for the last 5 days and haven't changed anything in my plan. Help needed.