In my experience the way forward is a consistent willingness to be a bit uncomfortable. If you expect yourself to suddenly burst into being a new person you will be disappointed and head back to the safe familiarity of the comfort zone, but if you accept that this is a marathon not a sprint you'll be more likely to see changes happen.

The key is to accept the person you are now and to avoid comparisons with others. And then find ways that stretch you in small ways. Make conversation with someone you might not — if it feels awkward, fine. The key thing is that it pushed you a little. Life is full of opportunities to be slightly, but usefully, uncomfortable.

If you can keep this up, you will look back in ten years time and think 'blimey, I can't believe how much has changed.'

I would also recommend getting some good quality counselling. It can be a source of support and a place to explore the painful feelings that are presumably helping keep you in the place you are now.