CONGRATULATIONS!!! i am sure you will do fine! as previously stated, you managed the leap from no bub, to new bub im guessing you coped well with that? then you should be fine with no 2! i found its usualy just your brain over thinking the situation, therefor making you stress out!
my boys are 19 months apart, they are now 3 and about to turn 5. i did freak as i wasnt sure how i would manage having 2 under 2, but my imagination of the situation was alot more dramatic then reality was!!
im now expecting no 4, i am due one month after dd's 1st birthday so there will be a 13 month gap, i have already been threw the stressed freak out "how will i cope with 4 and 2 so close!!" but df just kept reminding me how we have maneged going to one, ect and my mind has calmed down! (pluss he has started helping ALOT more, that or ive just noticed!) maybe let your other half know that you need him to be able to help as much as possible, might help put your mind at ease!
remember: you are a woman, us women can do anything!!