I agree with the others. Definitely talk to your mum. I was in a similar position many years ago and my Mum floored me with just how supportive and caring she was.

From the sounds of it you will be needing to make a decision on keeping this baby on the basis that you're doing it without your ex's help and support - having a baby is definitely not a reason to try again. And if that's the case, his wishes shouldn't come into your decision. I think its really important to make such a huge decision being honest about how its going to be. MR's suggestion of counselling is a very, very good one.

As for what you've done since conception, until the placenta takes over our babies are actually very well protected from what we do to ourselves. What's done is done, so be honest with your GP about it but there's no need to beat yourself up about things that can't be changed.

Good luck.