9weeks feeling the blues :(

Hey everyone, I'm pregnant with baby number 2 and my pregnancy so far as been COMPLETELY different than my first. Im experiencing a lot of nausea, acne, fatigue and tender breasts. All of that I can manage but what I'm having a hard time with is this constant feeling of sadness. My husband and I were actively trying for baby 2 but after the first month of trying I had convinced myself this wasn't the time (we had just moved into a new place and money is kind of tight now) but then surprise! I don't know if it is because of convincing myself that we should wait or if it's hormone changes but this sense of depression has come over me. I try to stay happy for my toddler (boy, 3) and my husband who is so excited for baby number two but I cry so much and just feel this overwhelming sense of sadness. We went to our first OB appointment yesterday and her response was that it's normal and might mean I'm pregnant with a girl. I am feeling so guilty for feeling depressed about such an amazing blessing and I feel bad because I don't ever want this baby to feel unloved or unwelcome. Help :(