if you can, write things down, keep a diary. say what you feel, what triggers the worst feelings, what makes you feel happy, what makes it easier to cope, what the most difficult things are, how you felt before becoming a mum, why you feel compelled to watch programmes which are clearly distressing you.
I know this sounds like a mammoth task, but believe me, it could help massively. You will be able to see what's going on in your head and, in your better moments you may be able to look at your entries and work out coping mechanisms etc. MOST importantly, you'll be able to show the diary to a professional who will get a clear picture of what your mental state of mind is.
If you can't face going to the docs/receptionist etc, send it by post with a covering letter. Speak to your health visitor.
the right medication could literally change your life. it will help with the immediate problem of how you're feeling, your paranoia and what sound like anxiety attacks. once these are a little more under control, you can start working through why you feel this way and what you can do to get better.
depression and similar issues are so scary to people but think of if like this. if you'd fallen down the stairs and broken you arm, of course you'd go to the docs - you'd be mad not to
depression is exactly the same except you can't see the 'injury'. Not the best of examples,i know, but best way i could htink of to get the point across.
And most importantly, you more than most parents, are in that category where you really need to be able to cope and give strength and hope to your darling daughter.
Where you offered counselling or given details of support groups - they can be a true life line. would your dp come to counselling with you?
I hope this has helped a bit.