Mental health

I never had any mental health issues before pregnancy but I'm pretty sure I'm developing prenatal depression. I'm irratable, crying alot, having stupid thoughts although I know I won't act on them but still I hate the fact I've had them. I'm going to speak to my Dr on Monday but I honestly don't understand why it's happening to me. I've got so much in my life to be happy about yet I'm miserable. It's frustrating. I want to be happy and want some energy. All I can think it's down to is this pregnancy being rough. I've had hypermemsis, lost 1.5 stones, although it's easing but I'm still being sick. I have a very stressful busy job which I'm struggling with and I've now developed spd/pelvic gurldle pain. Could this really be the cause of it all.... and will it get better?? I'm reluctant to go on any medication because I don't want to harm the baby but I know the talking therapy has long waiting lists. I think if I wasn't is constant pain and had some energy it wouldn't be so bad but there's not much I can do for that either. I'm not even that far, just 22 weeks. I never had this with my 1st child although I did have hyperemesis then but it didn't last as long. Any kind advise would be appreciated right now as I don't feel in a good way mentally. I need to pick myself up but I just don't know how... I have spoken to my partner about it tonight, and cried alot whilst doing so. Maybe now I've spoken out I will feel some relief.