1 month follow up appointment

So, I had my 1 month follow up appointment today with my doctor. It wasn't a good visit, in my opinion. He didn't understand why I haven't lost any weight since my last visit 3 weeks ago. I told him that I had the same concern. I explained that I had in fact gained weight and just lost that weight this last week. It was really a depressing visit and I just wanted to cry while talking to him. I know he didn't mean to, but he really made me feel like I'm failing at this. I'm trying my hardest. I still can't eat more than 600 to 700 calories a day, I don't snack more than once or twice a day, and I get most of my protein in. I try to get all my fluids in, but it's been hard. I have even given up coffee (which has been really hard for me) because I know that if I drink coffee, I won't drink water as I tend to sip my coffee most of the day. Sometimes I feel like I'm crazy the way I read every damn nutrition label making sure that I don't eat something that has too much of the wrong things in it and choose something that has all of the right things. He kept talking about liquid calories and I just wanted to yell and tell him to shut up about that because the only liquid I even drink is water. I miss juices and I can't stand adding those crystal light flavors to my water because of the after taste I get from them. I know he wasn't trying to be cruel, but after this visit, I just felt so defeated. I had to fight my own thoughts. I kept thinking about going out and buying the most unhealthy, greasy, fattening thing I could from a fast food restaurant on the way home, but I couldn't bring myself to do it. Of course, the one thing I have always had my entire life is wheel power of not eating what I know I shouldn't be eating, so I didn't stop. I just went straight home and started working again. I'm just really worried that the weight won't come off.