Sometimes daylight bulbs aren't the right ones. I have some Sylvania Daylight Extra 13w spirals that are only 3500K. Plants need 6500K or so, so look for bulbs no lower than that range. The "K" is "kelvin", a rating of the color temperature of the light. I looked and looked and looked for anything higher than 6000K at WalMart and HomeDepot. I found lots of bulbs that didn't specify the kelvin rating, and the ones that DID specify were way too low.
If you can't find any around 6500K near you, you can order them online ~ I've had good luck with 1000bulbs.com
~ just a few bucks per bulb (if I'm remembering right, less than two bucks apiece for the 15w I got and less than three for the 30s and shipping was reasonable). I bought some of their 15w 6500k (or was it 6700? Can't remember) and their 30w 6500k and have been playing around with different configurations above my ten gallon tanks (I have five total). One tank has 15w plus a little dappled sunlight, another has two 30w and still another has two 15w. I'll soon be adding lights above another two ten gallon tanks, so will have more room to fiddle around with light levels and learn about them.
One question I have about your plants, Tina ~ when you bought them, were they all under water (submersed)? Or were some of them kept out of the water (emersed)? Some plants are grown emersed and some of those will melt when they go from growing emersed to growing submersed. Also, I've found that some plants will melt from transplant shock, but they'll get over it eventually ~ that very thing happened to my hydrocotyle (pennywort). That really sounds more like your problem since it happened so fast. Lack of light in my experience takes a lot longer to make plants melt, and they'll grow long and leggy before they finally give up and start dying. You still need better lights, so I'd go ahead and get them as well. But I thought I'd also mention the possible other cause.
And welcome to the planted tank world (and the forum, too!
). Soon, you'll be just like a lot of us here and have MTS (Multiple Tank Syndrome). It only took about three months for me.