Two steps forward, five steps back: insomnia and panic

Hello all,
First of all I feel bad that I only really come here when things are really bad.
I had been feeling a whole lot better than ever until recently, increasing lengths of nights spent awake then almost zero sleep last night and a horrible quasi-panic attack where I started hitting myself. It seems I get SO angry that I end up panicking sometimes.
I study part time for a PhD and also work. Next week I have a panel for my PhD (feedback in a viva type scenario) which I am dreading, this week at work I have been left alone for the first time (although my new job is not so stressful). We're also trying to get pregnant and my period / negative / positive result is due on Sunday.
So, logically I can see why the panic is building. But emotionally I feel crestfallen, as if everything has gone wrong already; on top of that I am rehearsing old mistakes and arguments over in my head as extra punishment for myself.
I really thought that with my three months of CBT late last year / early this year I was 'fixed' but it's just so frustrating to realise I may have to live with this forever.
Just needed to share with some people who would understand.