Hi, that really sounds like a form of anxiety. OCD or Generalised Anxiety Disorder, it sounds like you're doing the right thing by having a blood test and beta blockers do help..
Try some distraction techniques, each time you feel you need to check your finances or clean, perhaps go for a walk, put some radio on and have a sing or come onto these forums and try and take your mind off of it.
If the symptoms seem to be getting worse, ask your GP if you could be referred for some Cognitive Behavioural Therapy (CBT), it's a block of short counselling but will deal with these intrusive thoughts and turning the negative into positive. Also have a look at mindfulness meditation, I was a skeptic at first but feel that this along with anxiety meds and therapy are fantastic for overcoming panic & anxiety.
Also anti-depressants can help anxiety and also regulate time of the month, when for example I find my anxiety is worse.
Most importantly, lots of self care, bubble baths, do nice things for you, tell yourself how great you are !
I suffered from GAD, Chronic anxiety and 'was' agoraphobic for many years, am also primary carer for my Son and can assure you that nobody has undermined my parenting or had concern for my ability to be a Mum because of anxiety or my mental health issues.
Good luck and well done for speaking with your GP, it sounds like you are taking control. :)