I'm not sure if these are things you've gone over with your therapist or not, but I have a few comments I'd like to make.
the thing is, I can't stop feeling left out when I'm out and about with them.
Can you point to any specific behaviour on their part that makes you feel left out? Or is it just a feeling you get? If it's only a feeling, then the rest of my points apply. If not, ignore.
I tend to get very conscious of my behaviour and sometimes analyse it afterwards
I can almost guarantee you that they're not paying nearly as much attention to your behaviour as you are. People tend to be very self-focussed. In normal social interactions, they're too busy paying attention to themselves to be analyzing the minutiae of your behaviour.
which often leads me to the conclusion that people just keep me around as some sort of back-up friend.
Now, in my head I know this is not true
So, your feelings are leading you to false conclusions. You know this to be the case...
but I can't stop feeling like it is.
So what can you do to stop feeling this way? What steps do you need to take? Changing your self-assessment, or consciously stopping your inner dialogue before you get to these conclusions? Would talking to your friends help?
As a result, I'm not always having that much of a good time when I should be enjoying myself.
I don't imagine you would be, if you're that focussed on all of these things, rather than your friends and what you're doing with them! Kind of hard to enjoy yourself with all that going on in your mind.
And as a result of that, I tend to be a bit too distant towards other people and not very assertive when it comes to going out with people.
This is where incorrect thoughts on your part eventually lead you to behave differently, pushing people away in subtle ways. They pick up on this, and eventually it becomes a self-fulfilling prophecy, creating the very distance that you initially feared.
The thing is, I'm relaxed and outgoing enough to meet and talk to people. I just have problems handling the day to day dynamics of long term relationships. Now I pretty much know where these problems are coming from (hooray for shrinks
), and if you know the cause you're well on your way towards the solution. But I was just wondering if other people have problems like this and how you deal with them.
Sounds like you've done some excellent work with your therapist if you know where all this is coming from (the way you worded that, that's what led me to the assumption that all of this is based more on invalid thoughts on your part, as opposed to behaviours on the part of your friends, and hence, this lengthy post).
How I would deal with all this is by utilizing the knowledge that I have regarding social interactions, and trying to be as objective as possible about perceived slights - assessing whether they're actually valid, or if it's just me being paranoid. If it's the former and I felt that these thoughts are valid, I'd probably try to talk to the friend(s) about it, if I felt close enough to them to be able to have that sort of conversation. It could be that they have no idea the things they're doing are making you feel that way. If I didn't feel particularly close to them, and felt fairly certain that their behaviours were just plain thoughtless on their part, I'd probably distance myself from them, and cut off the friendship. What's the point of continuing a friendship that makes you feel bad?
If these indeed are invalid feelings with little or no basis in the behaviour of your friends, then as I'm sure you know, that's an individual thing that needs to be worked on, which you're obviously doing. It'll take time, but you'll get there. It's not easy unlearning years of faulty relationship patterns, but if you keep at it, it can be done.
One more question - has your therapist ever suggested group therapy? That can be invaluable for assessing, treating, and learning about yourself and your social patterns, and developing new ones.
Good luck!