So my husband is busy at work these days, even working weekends, and I'm tired of staying home or going to familiar places in Nova. I'm itching to go somewhere, anywhere!

I'd like a change of scenery for 1-3 days.
What kind of destination is feasible/ideal with a 4 month old EBF baby if I want to be by a beach or see some new sights? I've already visited Wilmington, Philly, Annapolis, Eastern Shore, Virginia Beach, Richmond, Baltimore, Atlantic City, Harpers Ferry, Fredericksburg. Any other cities worth visiting that I can just walk around or do something with a baby?
Maybe 3 hours away driving distance Rehoboth Beach? But DD is too young to have sunscreen so should I avoid beaches even with hats and shades? Would a state park be any meaningfully different protection from the sun wise??
Maybe a cruise from Baltimore? I just looked at some and right now there's a 7 day cruise to Bermuda. But it's a smaller ship and I'm thinking 7 days is too long to be stuck on a ship just baby and I, since there's no babysitting and I can't do much.