Struggling in the second trimester 😔🤰🏼

Guys I’m really struggling in this trimester (second trimester) 🤦🏼‍♀️ I’m currently 20 weeks pregnant and lately I’ve been experiencing such bad dizziness when walking about! I popped out earlier and all the sudden became short of breath, dizzy, breaking out in a sweat and suddenly feeling like I was going to faint - I had to walk back to the car to sit down!

I’ve been searching things and loads of different causes are coming up, I mean I’m classed as “obese” so it could be my weight but it’s never been an issue before 🤨

I’m based in the UK, so the community midwifes aren’t open after 12 and so I have no one to call! Should I be worried or not?