From personal experience, it is often better to be alone than being around the wrong people.
Particularly if they are opportunistic users or bullies.
Happiness comes from within, from the mindset you choose.
Also from your hobbies and the positive actions you do.
Doing small things to improve your local surroundings, helping others- not just humans.
I've lived on my own for years, my best friend works abroad and can't often come back to the uk.
I feed the squirrels, ducks and swans.
I also enjoy collecting toy animals, reading, cooking, painting and photography.