Not sure if I have eczema on my lips or it is something much more serious?

[Skinhelp1234]

I'm 22 years old, sexually active and have always used a condom during intercourse but not during any oral activity. I recently started working at a new restaurant where in in the hot kitchen in front of heat lamps in tight clothing(jeans, black tee shirt, gray button up shirt tucked in, and an apron that starts at the waist and goes down to my ankles). I surf all year around even in the winter here in New Hampshire(thick wetsuit, good, gloves, boots). Starting in January I started to get very chapped lips. In the shower it looks like wet dead skin around my lips(mostly on the bottom lip). They dry up if I don't constantly put Chapstick on. I was very scared it was something more than chapped lips. I had blood work done to see if it was std related, everything came back negative. A dermatologist diagnosed it as eczema on the lips. Perscribed me to a steroid cream to apply 2 times a day. It has helped but has not fixed the problem. I've been extremely stressed out about this condition, thinking that it can still be something much worse than just eczema, even after testing negative at my primary care physician. Every morning I seem to have a very dry mouth, my hands have been a little shaky, dandruff has been worse than before. Any help is really appreciated. I'm new to the site so please inform me on anything else I can do to help explain further. Could this be std related? Will it be over once the weather continues to get warmer? Could me standing in front of heat lamps cause this or make this worse? Crohn's disease? Scabies? Diabetes? Vitamin deficiency? Surf equipment related?