The right sort of friendships will improve your self-esteem.
The support you can get, be it through advice or just being there for you to listen, is good for your health and mental well-being.
I know it may not always be easy to meet people you can trust but the sense of belonging, purpose and self worth of a good relationship will boost your self esteem.
Whether times are bad, such as going through divorce, redundancy, firing or bereavement a good friend will support you and encourage you to avoid poor lifestyle choices.
Celebrate the good times, support each other during the bad.
Just knowing someone is there for you can massively enhance your life.
There are many ways you can develop new friendships.
The key points here are important here.
Treat people how you want to be treated.
You must build trust by being honest to yourself.
Secondly, you must get out there into situations where you can meet people.
Unless you want virtual online friends you will not get anyway sitting at home moping about.
So go take your dog for a walk and say hello to the people you see.
Join a local gym and say hello to the people that you pass.
Catch up with people you want to get to know better, arrange a lunch date with them.
Accept all invited you get for a month, just say "Yes" and see where you end up.
Volunteer at places where you enjoy the subject like a museum or community centre.
Get surrounded by people who like what you like.
Join that cause you often find yourself ranting passionately about.
Do that hobby you always wanted to do.
All the above ideas have the same principal, go hang out in environments where like minded people will be.
They will understand you and therefore more likely strike up a friendship.