Hi - I don't really know what to advise you, but I do feel for your predicament.
The only thing I can suggest really is that you sit down and write yourself some pros and cons lists to help you think things through. You could also see if you can get some counselling on the NHS through your GP. It might help you to untangle the issues.
Were you and your ex together for long? Will he support you financially if you have the baby? Were you close to his family - would his parents support you and your child?
You say you have no support from family or friends; have you spoken to them about it? I don't know, but it's just possible they'll be more supportive than you think.
If you don't feel you could go through with an abortion have you considered giving the baby up for adoption? It would be hard, but perhaps weigh less on your conscience than abortion. You would know that the child was going to a loving family and you would be able to get in touch when the child was older.
People do manage to bring kids up on their own, but it is hard work. There is some financial help available - you could talk to your local Citizen's Advice Bureau about that - but it will still be financially difficult.
In short - good luck with whatever decision you make.