Well you spend too much for what you earn then.
Too much rent/mortgage- too big a house/in too expensive an area
Too much on car- car too big/flash / repayments too big
Too much in clothes/accessories
Too much on household goods
Too much on other extras or things that are not necessary
Either you have been an over-spender and it has caught up with you and you haven't reduced your outgoings according to your incomings, or your circumstances have changed .
Either way, you need to sell stuff and reduce your outgoings- not take on debt-or get a better paying job.
DH and I had to reduce our outgoings when I had DS1. I saved a year's salary and had a year's maternity leave then gave up working. We had DH's salary - which meant we'd lost our biggest salary so we were more than 60% income down. I was lucky in that a redundancy came up at work as I was making the decision and I volunteered so that gave us a lump sum but not that much.
We just managed with much less I became a very careful shopper, we stopped buying clothes for me and DH, we cut out so much 'stuff' that we frittered money on. Got rid of a car. Stopped going away for any holidays at all for 2 years. Barely went out for meals, no takeaways, gave up subscriptions to gym, stopped buying anything we didn't need.
What helped was we had been paying our mortgage down before we had DC so were not stretched by that.
He worked hard had two promotions in 3 years. I then had DD and stayed at home but started doing consultancy work one day a week, then two and eventually 3 . We had 3 DC in 5 years and by the time DS2 was ready for school I was back up to 4 days - two working from home.
It was hard but I went back full-time when DS2 started school. We are better off now because DH has a much better salary than he had then but we were much more careful for about 3 years. Frankly we had been wasteful of money before we had DC. We are now good savers and live well within our means.