Ireland Gems in just 4 days?

We have 4 full days, into Dublin on a Friday morning, leaving early Tuesday. Wanting to see Galway, a few castles and the countryside. My sweetie is there for work so corporate gets to help with the bill. ;) Great romantic restaurants and hidden gems would be wonderful!!! THANKS!! We're excited. PS- it's in April so weather may be a bit "soft" as they say