Tinkly, sounds like a difficult choice, but it sounds like your own instinct is telling you to give up work for a while and stay at home with baby. Growing a baby is hard work too! Don't feel guilty for being at home while your partner is working, trust me, being at home with a small child and running a household is just as hard if not even harder than any job you can do outside the home! All that said, I fully sympathise with your need not to be fully dependant on your partner, so maybe a good idea to do what you can to keep contact to your jobs do when you're ready to return to work you are in a position to do so. 8 weeks sounds a bit too early though if you're already feeling this way.
Managing financially on mat leave can be difficult, but buying baby stuff second hand and realising there's so much you do t need at all makes it easier. If you breastfeed, all a new baby costs is a few one off buys like bed and buggy and clothes, most can be got second hand or discounted . if you arent too particular about it. With my DD I was so particular and fussy about everything and spend quite a bit and now it just makes me laugh, I realise it really doesn't matter if you have a co- sleeper bed or a normal cot (unless you have a c section) it does not matter if the baby clothes is brand new or second hand because they grow out of it so quickly and half will be stained with poo that not even days soaking in Vanish will help. eBay, second hand stores and NCT nearly new sales are great, and dont be shy about asking friends and family for hand me downs. The only thing I'd say is important is the kind of buggy you get if you're planning on doing lots of shopping and walking with it, it's important that it has a decent basket underneath and a smooth ride. But if you have a car even that is not so important. All small children really need is your love and attention.
Also, you may find other expenses go down once you stop working, maybe this is not so much in your situation, but for me it did because my job requires me to look v smart everyday so I had to regularly update my wardrobe, I take the tube every day which is expensive and I'm always too disorganised to bring a packed lunch and spend loads on lunch and coffees etc, especially when pregnant. When your on mat leave you spend more time at home and at the most you spend on meeting other mums in cafes or a few baby activities but this can easily be circumvented by meting at people's houses, and most areas have a decent selection of free baby activities too. Do t worry you'll be fine! And don't feel pressure to work beyond what you can manage. If this sounds preachy it's just because I'm speaking as much to myself, am under pressure to perform better and work harder st my job for the remaining 8 weeks and struggling with saying no and maintaining that all I need to do is the hours I get paid for and that I'm not going to take on any very big and demanding tasks right now at the risk of making myself exhausted and risking the health of my baby. It is hard in this man's world to remember that as a woman you have a right to protect yourself and your unborn baby and put your pregnancy first at all times, but they is what we should do and just close out ears to internalised nagging guilt for not being able to perform to the same standards as when we're not prevent. We're growing a new human being and thet is already a major achievement.