What should I do?

Hi, it sounds like you are finding it hard to adapt again now your relationship has ended. 

I can imagine for you there are a few parts of this.  One being the relationship break down itself and losing someone you care about.  The judgement about being too comfortable with them earning more money and also loss of the children and the bond you had with them, and now having to adapt to life on your own.  The loss of many things you had which made you happy.  Potentially life was busy  but now it is feeling quieter and emptier and now you are having to change and adjust to this new way of being and managing the loss.

I am thinking that part of the process is coming to terms with what has happened.  Perhaps it was outside of your control, perhaps you didn't know it was going to happen, the unexpectedness of it all.  It will take time to adjust and find out who you are again.  What makes you happy, beginning to fill all the spare and empty time you have now.  It won't always be like this, emotions fluctuate with time and are forever changing.

For you right now, it is important to explore those feelings, to work out how you are feeling and how you are managing.  In time you will notice small changes that help you to find purpose again.  To explore the feeling of loss you have and how to manage this, and also manage other areas of your life which you may be feeling are hard to manage as a consequence of what has happened.

You built an attachment, not just with your partner but with their children too.  You describe them as your best friends.  Here there will be new adjustments needed, you have lost a partner and friends and maybe feel like there is no one left for you to support or even to support you.  Having said you are not good at being alone, tells me you are self-aware.  We can look at this and increase your awareness to promote personal development within yourself to help increase your self-esteem and confidence.   

I hope this has given you some ideas of how counselling could potentially help you get through this time of you life.