Happy is the high opposite of sad.

I prefer to aim for contentment as it's more stable.

Contentment: Contentment is an emotional state of satisfaction that can be seen as a mental state, maybe drawn from being at ease in one's situation, body and mind. Colloquially speaking, contentment could be a state of having accepted one's situation and is a milder and more tentative form of happiness

You are correct in that paying attention to the emotional well being of those in your close circle have tremendous pay offs if you provide a safe productive environment for them to thrive.

Sometimes it's as simple as just quietly listening to someone and not giving advice but reassuring them that they got this based on past challenges they overcame.

Have a great day and may you find contentment on this crazy planet!