Struggling with work - bit of a rant!

I'm having problems with severe BH when I walk for more than a few minutes or when I do any kind of exercise. At the moment there's no parking at work due to travellers in the car park, I spoke with HR yesterday because my boss wasn't in and they've said that I should work from home until the problem is resolved. Then today my boss came back and kicked off at me about how I'm not entitled to parking anyway so I should be there no matter what. We normally get on so well, but we've since I got pregnant he just makes me feel guilty about it and about taking any time off or working from home, even though I'm entitled to. Originally I was told I could work from home once a week, but he kicked off so much and made me feel so bad that I was there every day, even when I wasn't well enough. I've ended up just saying to him if he has a problem with me working from home due to me not being able to walk to the office then I'll have to get signed off by the doctor, which I don't want to do because we need to be saving money ready for maternity leave. I feel see stressed by what should be a really simple situation! 😭 Sorry for the long rant ladies