So Frustrated!!!

So yesterday I was 23 weeks pregnant. This is an exciting place to be, but I could not get myself even remotely excited about anything yesterday. I don't know if it is just pregnancy hormones or if I'm just depressed, but I can't seem to get out of this funk I'm in. I do so much all day long and it looks like I've done nothing. Of course if it looks like I've done nothing people are going to assume that to be true, (even though it is far from it)there just seems to be no appreciation for the wife/mother anymore. No one says this to me, but I can sense it in the air around me. It is so frustrating. I'm miserably pregnant with my fourth child and each pregnancy has been harder and harder because I've been larger and larger with each one. I'm definitely grateful to be having my little Olivia, I just wish I wasn't so miserable. This on top of the worthless feeling I have trying so hard at home and never succeeding is leaving me feeling like absolute crap. It makes me wonder if this is the way most women at home feel or if it is just me. I also wonder if on any given day I can walk into other SAHM's homes and expect to see a mess just like mine or if my house is truly always as bad as it seems to be. I can't get past these feelings of awful guilt at what a bad job I think I'm doing at home. If I didn't have spots in my home (such as the carpets) that just refuse to come clean no matter how hard I scrub, I wouldn't feel so bad, but I do have such terrible messes that just refuse to come clean and it leaves me feeling dirty all day long even if I do manage to keep the house picked up and clean for more than 10min. I thought that things would get better once all the big kids went back to school, but now all my kids are sick. School germs are the worst. I hate to complain so much. In my heart I know I'm blessed beyond all measure. I just wish I could get my body and mind to realize the same thing. Anyways I guess I've rambled enough.