Which demonstrates that you in fact are bad with money, so the system is working as intended. If you don't trust yourself with day-to-day spending, why should a lender trust you with a loan representing months or years of income?
Keeping an eye on your spending is great, but you can equally do that with credit; it's easy to look at or download transactions in your credit card app or website. Unless of course you don't trust yourself not to overspend, in which case my point stands.
You are aware that interest rates have been incredibly low for years? They have to go up to keep a lid on inflation, and the BoE needs to be able to do that without worrying about mortgage borrowers being overstretched.