I'm not sure what the heck is going on here.

I've been pretty blah around the house, slipping on laundry and dishes and all that, and my wonderful DH has been really picking up the slack, without me asking or anything. He works all day, comes home, plays with DD, usually does laundry, or dishes, or general cleaning - things I should be getting done while I'm home, but I'm not. I'm feeling like a blob
I've been really busy the last few weeks, selling horses at a farm over an hour away, so I'm constantly having to drive there. Last week I had a whole expedition with breaking my rear window and it finally was really fixed this Monday. I also had my friends wedding that I helped plan and do a lot for a couple weekends ago. But for doing things around here, well, I'm not - and I really do have the time.
So I guess I'm getting things done, but not the things I also should get done. Some days its a pain to get dinner around in time for him to come home. I mean, it's not like it's that hard - most of our meals take 30 mins to make and are simple - what he likes, and I do too.
Last night in bed, he asked me if he had done something wrong.

NO! He's doing everything right, perfect, wonderful, and I'm making him feel like I'm punishing him or something because *I* feel like blah and don't have any motivation. What sucks the most is that my sex drive has way dropped in the last couple weeks, and his has gone up a lot since he got home from hurricane work. I always "do it", but I just don't enjoy it as much - I'm just too tired and too blah. I'd rather not do it it seems - before it seemed like every other week was doing pretty good, now it's at 2-4 times a week, and I just don't have the drive for it....and it sucks because I know I should be enjoying it - I always have before! He is, well, um, pleasing.

He even thought that I didn't want it much because he can't "last" long - which really isn't a bother to me - it's always been that way, and he makes up for it in other ways. I can't even remember the last time I initiated - before, I always was starting it, now I never do.
I told him I would call our GP today - who dxed me with PPD, and I've been on Zoloft (50mg/day) since last April. This isn't near as bad as the PPD was before I got it treated - but it's got a lot of the same underlying feelings - tired, don't want to do anything, resentful when I have to get up to take care of DD, glad that DH is helping, but resentful of myself for not doing what I should be. I'm wondering if upping my meds through the winter might help a bit. I've always had issues with fall/winter, and here in MI, the weather SUCKS and it's generally quite dreary - perfect for that Seasonal Affective Disorder. I found a list of stuff, and the only thing I haven't really is the anxiety and weight gain - yet.
Symptoms of winter-onset seasonal affective disorder include:
* Depression
* Hopelessness
* Anxiety
* Loss of energy
* Social withdrawal
* Oversleeping
* Loss of interest in activities you once enjoyed
* Appetite changes, especially a craving for foods high in carbohydrates
* Weight gain
* Difficulty concentrating and processing information
Just....blah.