Hi OP,
It's difficult to advise on affording the weight loss medications as I don't know if you are already hugely frugal and single for example or have a family and have areas for cutting back.
You can save some money on the medication by using the "golden dose" (look it up) and by counting clicks when you move onto stronger doses. The meds are supposed to be used in 30 days and can be kept out of the fridge once opened. Some people are comfortable pushing this by keeping meds in the fridge but even within 30 days you can take 5 doses not 4.
Not just due to weight loss injections but due to cost of living/my hours reducing/need to save for university for my son we have cancelled subscriptions (review all of yours), cancelled general savings for the kids (didn't save for ourselves anyway) reviewed phones and broadband and have fewer paid days out/meals out etc.
I don't feel guilty about cutting back financially for WLI. I work night shifts and have a child with special needs. I've been on Mounjaro and lost 2 and a half stone. Before Mounjaro I was putting on half a stone each year and I think this would have continued. I think I will now live a longer, healthier life and be able to work and support my family for longer.
I think most people will save some money on food. You will probably want to buy high quality food (meat. veg, fruit, dairy) in smaller amounts. Saving some money on the amount of processed food and takeaways.
Rather than working more I'd see if you can find savings anywhere to pay for it.
Also Retatrutide should be coming soon and is more effective than any meds so far I believe. Hope they get cheaper with time.