Client advice (self employed)

Hi ladies, I’m looking for some advice/reassurance I’m not being precious. I’ve been self employed for the last year, I started working with a client on a 6 month contract but it’s ended up rolling on for the last 10 months which is great! Initially I was meant to be working alongside fellow marketers delivering on campaigns and campaign planning which was what we agreed my day rate on. As time has gone by my MD has started to depend on me more and more, my workload has increased quite a bit (what went from managing 3 event campaigns has turned into 18), I’m now partly managing the marketing team and I’m finding the demand for updates from the clients quite overwhelming, not to mention I’m now in charge of web updates and liaising with different team members on data cleaning, managing expectations and updates across the sales and production team and more… I’m only meant to be part time in this role, I’m also 27 + 3 days pregnant and things take me longer to do at the moment. My brain is just not with it! When I take days off I’ll be whatsapped and the second I log on sometimes called? This morning I had a stress dream that I was asked to start working at 6:30am 😂 I’ve tried handing some of my work off to my team as I’m only with them for another 9 weeks but I ended up having to take it back because my fellow marketing manager was overwhelmed and couldn’t meet the deadlines. I feel really conflicted as I love how much the team needs me but they can’t promise me a role to come back to in the new year, I am meant to be working part time and I seem to be responding to people 5 days a week not to mention it’s really intense as our event is 5 weeks away… usually I’d crack on over the next 5 weeks and just get through it although now I’m pregnant it’s not really just about me and I need to make sure I’m not taking on too much or getting too stressed. Is anyone in a similar position or has been? How did you manage to keep a client happy while also making sure to not spread yourself too thin?