Sorry but isn't that just life? (Not having enough disposable income). Any spare income I get, I wack in to my savings.
You pay a mortgage so that when you retire, hopefully your mortgage is paid off and you can live in your owned house rent free and just need to pay the other bills.
Fuck paying rent all of your life, you are filling the pockets of a landlords and rent is typically higher than what you'd pay on a mortgage.
If you are struggling to save then make sacrifices. Life is tough. It is funny seeing people in their 20s moan about the housing crisis when they're dressed in designer gear and have just got back from a trip to Thailand and probably have Glastonbury tickets sorted for next year.