Goodness, 5 miles a day? How'd you work up to that and how long did it take you? I'm not sure I can even run a block.
As for how to get over that fear, I gotta say what worked for me is the band aid method - you gotta just tear it off and get that initial pain out of the way. I am not a pool or beach girl, but my husband really wanted to go to Jamaica for our honeymoon. He'd already indulged my Disney obsession for a couple vacations, so I went for it. It was the first time I'd been in front of people while wearing a swimsuit in such a long time. I felt super self-conscious, but I found that people didn't stare and they didn't care. I would take off my dress and hop in the water as fast as possible, but after a little time, I was walking around in my swimsuit and visiting the bar in my swimsuit. I think all it takes is that initial "OMG, I can't let people see me like THAT!" - Then you realize nobody is paying attention and there are other fluffy people all around. Be proud that you're getting healthier by being active and let that boost your confidence. Plus, you're there to spend time with your family and build memories with them - don't let anything get in the way of your doing that.