Pregnant with second child - feeling sad for 1st born

So let me start by saying although my subject doesn't sound happy I am completely blessed and happy to pregnant once again. My sadness comes from learning to spreading the love between 2 children vs just the one I have now. My son is now 15 months old and I feel like I've had such a strong bond with him since the day he was born. I fear that that will all change once baby #2 comes into the picture. I don't want to take any love or time from him nor do I want the same for the baby that's on the way. I had a c-section my first pregnancy which means this one will prob be as well. The thought of not being able to hold my son the weeks after I deliver makes me so sad! I don't want him to feel pushed off to the side as soon as his little bro or sis come. Is this a normal feeling? My hormones are crazy so that might have some play in my thoughts. Any advise from anyone pregnant with their 2nd or parents with more than one child?