feeling defeated

About a month ago I was on a serious mission to lose 15 pounds. I got down to 151 (goal was 140) and then I got sick. The infection was misdiagnosed and I ended up being on medication for a month, with little energy, and overall exhaustion. I just got better this week and have been working out again, but for the first time in about 6 weeks.
Over the course of the 6 weeks I actually didn't gain much weight.....about 3 pounds. Then on the weekend I had an anniversary with my husband, and I ate and drank alot more than I usually would (usually drink nothing at all). On Friday I weighed 154 and on Monday I weighed 159. Today (Thursday) I weigh 157.
I FEEL different, I FEEL horrible. My stomach is bloated and huge, my clothes arent even fitting the same.
I know how to lose weight but after working so hard and now being up 6 pounds I am just devastated. I feel scared I cant do it again.
Is weight gain gradual? I just dont understand how this all seemed to happen at once. I really want to get back to 151 but I feel scared and so frustrated.

It's probably not as bad as you think. A lot of times when we indulge for a day or two because of a special event, we enjoy foods that are loaded with sodium and other bloating nutrients. It may take a week to get it out of your system if you are drinking plenty of water and watching your caloric intake. Chin up, it will come off again! To gain one pound of fat, you will have needed to consume 3,500 calories over your net calories. I doubt you ate 10.500 calories... so that means something else is going on with your body. Read this: http://www.myfitnesspal.com/blog/bjohs/view/small-weight-gain-don-t-panic-127354. You may find your answer in there. If not, know that the MFP community can help you stay motivated. Make friends here and they will be with you every day to cheer you on and keep you inspired! Good luck!

First, acknowledge that after a month on medication, it might take your body some time to get back to normal. Don't be hard on yourself. It was important that you enjoy your anniversary, especially after recovering from serious illness.

Think about where you are now as a brand new start, not comparing to where you were before your illness. It's time for you to begin re-inventing yourself again, healthier and stronger. Only a day or two of watching what you eat will get you past the bloating and feeling gross. Drink a lot of water to flush everything out of your system. Consider focusing for a couple of days on whole grains, fresh fruits, vegetables, and a small handful of nuts. It'll help you feel better and like you're taking control as you leave out the unnecessary fats and heavy proteins that take your body longer to break down.

Don't expect to drop the weight suddenly. It is a slow process, and should be. Anything else neglects your body and begs to be put back on just as fast. This site encourages us to do it right, and we support each other in that process. Don't give up hope. Keep plugging away. You'll feel better soon.

I too got down to 153 and back up to 160 and I felt defeated because I couldnt figure out why....I work out everyday and watch what I eat. When I joined this site I realized I had no idea how bad some of the things I was eating were when I thought they were healthy. I have lost the weight and am now lower than ever in the 140's. It works just takes time and dedication. :-) You can do it.