I have 17 months between mine, so a slightly bigger gap than you, but there were some things I did that made life easier:
Prepped as much as possible during the night or morning when dh was here, eg sterilised and made up all the bottles for the day (dd bottle fed)
Made a pack lunch for myself so I had something quick and relatively healthy that I could just grab
Toddler ready meals and batch cook stew/chilli etc in the slow cooker for ds' meals
Fed ds slightly earlier/later than normal to work around dd's milk
Double buggy so I could easily take both out during the day
Sky+ loads of episodes of fireman Sam to keep ds occupied whilst feeding dd. I also bought loads of cars, books etc that he could look at/play with on his own
Bought a swing for dd so she had somewhere safe to sit whilst I had a wee/made dinner/played with ds/changed ds' nappy/did some house work/had a rest
Accepted that dd would have to cry a lot more than ds ever did as I couldn't split myself in two
Kept ds in nursery for a few mornings a week so I had time alone with dd to bond with and get to know her
Dropped my standards dramatically re the state of the house: I just didn't have time to do it
Hope this helps. And if course, congratulations on your new baby, hope it all goes well 