To feel like I’m second best to everyone

[BlueberryElephant]

I’ve never been anyone’s best friend. I’m always the back up friend.
No one has ever wanted to marry me, I’ve had long term relationships, but they never want to marry me. I then later find once we’ve split up that they’ve proposed to someone else. I’m in a relationship currently but I think he is only with me because we have a DS together, also I think I was the only thing that came along at the time when we started dating.
I’m second best to my parents - my brother is the golden child.

I’m really starting to feel like I don’t matter to anyone. I’m no one’s priority. Even my DS seems to prefer his Dad and Grandparents to me. I guess the common denominator is me.

That made me really sad to read.. I can relate to the part about being second best as a child, or in my case simply hated, (my mother beat me regularly but never touched my sister I can’t understand it or get over it)
I married young though and boy do I regret my choice. But I’m stuck.
Not much help but I just wanted to say you aren’t alone in feeling alone and unwanted

I think the common dominator is the feelings coming second to your brother has left you with. Because all the rest of it, is just normal stuff. Lots of people don't have a best friend. Most people don't get a proposal in every relationship they're in and go through a number of temporary situations before settling down. Often exes marry other people. I don't know whether your current partner appreciates you. But if he doesn't, again, you're not alone. Countless women are taken for granted by men. It's not them and its not you. If I were you I'd do some work around the impact of your childhood because that's why you believe you're second best, not because you are.

Absolutely agree with @5128gap being the less favoured DC leaves people with a life long feeling of not being good enough, it's very unfair and really harms people's esteem and confidence. I'm sure your DC does love you Op, you're Mummy and that's a special place in any child's life, please don't tell yourself otherwise.

Because you perceive yourself as the common denominator doesn't mean it's true. You may have unconsciously surrounded yourself with people who are emotionally unavailable to you which has led to the outcomes you fear. Are you able to access some counselling? Also start reading round dysfunctional families. The Stately Homes thread on Relationships here is a good source of support.

You sound very down on yourself. Building up your self-esteem may give you the boost to make better choices in future ie choose more available people. Your childhood has probably programmed you to accept little from other people. This is fixable.