I'm happy being single.

[Wowenglish]

I wonder if "1" means "2", "3" or "4".
I wonder if "being" is gerund or participle.

1. I'm happy being single.
2. I'm happy about being single.
3. I'm happy with being single.
4. I'm happy that I'm single.

[Dozy]

I don't see any differences in meaning, other than the most hair-splitting ones, between any of these sentences.

I think "being" must be a participle in #1 and a gerund in #2 and #3.