Your happiness is often invaded. A sick person needing attention, someone who needs a visit, a person who needs an ear. Often people need reassurance and you are the strong one. But don't give up your strength for others. By continually being asked for help and giving it you'll be sapped dry.
Stay strong by drawing on the power that's around you but assess your priorities in transferring that strength. Sometimes you must say "No" to survive. You'll feel guilty but you won't be hollowed dry and end up ill . Sometimes we all need to reassess our lives.