Feeling down lately

For some reason, my baby just turned six months and I’ve been feeling really low emotionally. I’m familiar with depression I’ve had it in the past, and definitely had baby blues but that lifted pretty much after the first two weeks. Something feels different. I keep fighting with my husband and just feeling sad and anxious and crying. I am thinking maybe my period is coming back but so far I haven’t gotten it. I really hate fighting with my husband, even when I think I’m inthe right to fight with him. This parenting job is so hard and lonely especially if baby doesn’t sleep well that I can’t deal when I don’t have his support. He’s generally a great dad and husband but of course we have fights. I don’t know I’m just sad. I feel low. And I don’t really get it. We are going on a small vacation next week I’m not sure if that has to do with it. I do tend to get stressed and anxious with new things in the horizon but ... I don’t know. I hate feeling this way now that I’m a parent I feel like it leaks into my parenting. I become lazy and I feel like he picks up my mood. Sunday nights are never great for me I guess so maybe it’ll pass. Just throwing it out there in case anyone feels the same or has advice. 🤷‍♀️