J. .. don't torture yourself!
My girls are almost 4 1/2 years apart. and YES YES YES there is enough love to go around.. Never doubt the capacity of your heart. Now let me tell you.. I don't love my girls "the same".. I love each for who they are.. There is no favoritism, no scaling of equations.. They each get from me what they need.. (and more) and I get the same back.
They are great together too.. and love each other dearly (Not that they don't fight! lol) And will always have each other, even when my husband and I are gone.
BUT DO follow your instincts about YOUR readiness for another child. I needed to wait.. for MY OWN emotional needs..(If that makes any sense)
When she was going to preschool.. growing mentally and emotionally by leaps and bounds, I realized I was ready to do it all over again.. to go back to diapers and nursing, waking in the night and soothing a crying baby. I was anxious if I could love another child as much as I was consumed by love for my daughter. and guess what.. The answer was YES.
But ultimately it is YOUR decision when to be ready .. not your husband's .. he is not the one carrying a child, birthing a child and 24/7 raising the child. YOU need to ready or you will be resentful of your husband and the baby... Not a good way to go.
My girls are now 17 1/2 and 13... I knew after my 2nd daughter was born that I was done. I was 38, and so tired!! LOL..
Follow your heart on the timing.. and trust me that you will have more than enough love to give to both your kids...
V.