Weight loss tips!

I need to lose weight. I am 5 foot 2 and a half inches and I weigh 139 right now. I started at 145 this year. I got down to 128 a couple weeks after new years, but I gained most of it back...need help. I'm extremely picky and healthy when I eat. I work out 24/7, I don't know what I am doing wrong. I usually eat like once a day, or once every couple days, but recently I have been eating A LOT more than that....maybe that's the problem?? I don't know??