I'd also fit fearful avoidant, I think, although I don't exactly feel trapped in a relationship - sometimes I do - more a feeling of fear. I tend to avoid emotional (and sometimes physical) intimacy by choosing partners who will not provide it (then not asking for it), or choosing casual sex (which inevitably messes with my head), or avoiding relationships altogether. I might be preoccupied, tbh, it's really difficult to tell because I'm pretty confusing to myself! I tend to feel insecure but I extremely, extremely rarely engage in any of the behaviours of the preoccupied person and even when I do it's very mild. The reason I went for fearful avoidant in the end is because everything I do is for self-preservation. I tend to visualise the ends of relationships over and over again in order to 'practice' the "correct" response (no emotion) and 'keep a check on myself' to ensure I don't get too emotionally close (fear of dependence)/get angry at myself when I feel something (viewing such things as a repulsive weakness in me).

What I'm doing, with a therapist, is to isolate the thoughts that lead to my behaviour and feelings and challenge them.

So, my thoughts are things like:
- I will always be alone
- Relationships are temporary
- Emotions are weak
- I will get hurt if I don't defend myself
- Other people are always disappointing
- You can't rely on anyone

You then just need to notice the thoughts when they come up and recognise they are part of a maladaptive coping style, so basically just observe it and think 'there's that thought again', instead of believing it to be true.

If you have trouble identifying your emotions and thoughts - I do until they get really extreme - Mindfulness can help.

Hope this helps.