13 weeks & 3 days fainting and taking a fit

Hey I was wondering if anyone can give me some advice. I’m 13 weeks and 3 days pregnant and over the past 13 weeks I’ve fainted quite a lot. Roughly about 10 times. Today i was in the shop with my fiancé and felt really faint so i asked him to help me back to the car and after a few steps I collapsed to the floor and started having a fit. I phoned my midwife straight after and she said I’m still early on to go home and rest. I’ve been home resting ever since and I still don’t feel well or right what so ever and I am not quite sure what to do considering I phoned my midwife and she wasn’t much help. Am I over worrying and just need rest or should I be more concerned? Any advice would be helpful thank you! I live in the uk