I would not say it is.
Happiness is an emotion. Just is regret, sadness, solidarity, grief, etc. In most scenarios happiness is an attributed factor and result of struggle, but not always. Someone could have the worst life imaginable, but just as well be content. Anyone can be truly happy, no matter the situation. This does not mean struggle is dismissed as a factor in the becoming of happiness, however. Many things come from struggles, and happiness is a common emotion once the struggle is over.
This is only eight sentences, but it's a good start.
Summary of Act 5 scene 1
At night, in the king’s palace at Dunsinane, a doctor and a gentlewoman discuss Lady Macbeth’s strange habit of sleepwalking. Suddenly, Lady Macbeth enters in a trance with a candle in her hand. Bemoaning the murders of Lady Macduff and Banquo, she seems to see blood on her hands and claims that nothing will ever wash it off. She leaves, and the doctor and gentlewoman marvel at her descent into madness.
What happened In Act 5 scene 1
Suddenly, Lady Macbeth enters in a trance with a candle in her hand. Bemoaning the murders of Lady Macduff and Banquo, she seems to see blood on her hands and claims that nothing will ever wash it off. She leaves, and the doctor and gentlewoman marvel at her descent into madness.