OP - I am a bit like you. I did BF DD for 8 months (stopped after 2 months of morning sickness) and all was fine, I will have a 16 month age gap between DD1 and DD2 when she arrives (not till April).
I too have been thinking about what to do when the baby is constantly feeding and DD1 wants attention. But I am just going to put in the effort to try my best. If it all goes horribly wrong then so be it, will deal with that at the time, but I am def going to give it my best shot as if you don't, you might regret it, but if you BF and don't get on with it, you can just switch to FF iyswim?
Also, I am trying to concentrate on the fact that yes, the baby will feed a lot, but she will also sleep a lot too. So will make the most of the time baby is asleep by doing fun things with DD, and then when DD is in bed, I will spend time concentrating on the new baby. I know it doesn't always work like that but that is my general plan anyway!
Also, I started looking after a friends baby who was 7 months when my DD was 2 weeks and BF. Never had any problems there, although that was only part time.
I didn't have any support either, and now regret not knowing that there are people around to help. I am hoping to get more support this time IF I need it, but if not, I am going to make a fuss this time and not just get on with it like I did with DD. I was a lucky one who managed to do it even with no help, but a lot wouldn't have.