Lip infection! Antibiotics but I'm itchy, nauseous and the rash is spreading?

I recently asked a question this morning about my lip infection, I've been on antibiotics for two days, flucloxacillin, 1 tablets 4 times a day. I've been getting the common side affects, nausea, feeling sick! Although last night I had difficulty breathing whilst at work and my legs were very shakey.

My lip infection come back with a vengeance this morning when I woke up, I've soaked them with water and applied Aqua max cream (suggest by the nurse) my lips aren't itchy, but my whole face is, it's a red hive rash and has spread and continues to spread since I got the antibiotics.

I have 4 days left with the antibiotics, I know I need to go to the doctors again if it hasn't cleared up.

My question is do I go to work? I had Monday off and my boss was so angry at me... I went in Tuesday so he could see for himself the rash on my face and that I was unwell, today is my day off and I hope my lip and face clear up, I want to go in tomorrow but I don't think I can if I wake up and my lips are the same as what they are today, I've had this since Saturday, although it's not long it's a very sensitive part of my face. I've been drinking with a straw, it's painful to eat and I know I won't be able to treat my skin as well as I would at home compared to work. Should I go to the doctors sooner rather than when my antibiotics course ends in 4 days?

I am NOT trying to pull a sicky off work. When I wake up the weepiness of my lips have dried and they are yellowish! With the rash.