Pregnancy blues

I'm 27 weeks and I just been feeling so tired lately.. being pregnant is a blessing because your amazing body has created this child. But lately I just been so tired and overwhelmed that I don't think this is normal, my situation at home is great my boyfriend is supportive with everything , we've been planning a huge babyshower for next month. But even tho I'm so lucky to have him , being pregnant has made me feel like I'm on my lowest points in life, just grumpy and insecure about my looks, I've never felt like this in the past 6 months and I'm starting to feel like I'm changing my life and things won't ever be the same because I'm expecting a baby. This sounds harsh but I'm truly grateful to have this blessing but all these feelings have really taken over me