Hi hun
Congratulations.
You sound like you have came around to the idea, I think its totally natural being scared, even if you've been TTC for 2 years, when you get pregnant you'd still be scared because its a new experience etc.
I think that you are in a good place if you and OH have been together for 2 1/2 years, the same as me and my OH and I know that we could cope if we found ourself in your situation (wish I was tbh!!)
If I was in your situation I would probably be reading books about pregnancy etc. Not telling you what to do, just giving you my opinion. I've got a good book by Miriam Stoppard, not sure what its called but only cost £2.50 used on playtrade lol
Keep us posted on everything. Your boyfriend sounds wonderful, he will make a great father from the sounds of things.
xxx