my attic is basically a wind tunnel and it's driving me nuts

I've been trying to figure out why my heating bills are so ridiculous lately, and after poking around upstairs, I realized my attic is basically a sieve. Seriously, I can feel drafts everywhere, especially around the hatch and near the edges. I tried stuffing some insulation up there last year, but clearly that didn't do much. It's like the warm air from downstairs just floats right up and out, and cold air rushes in to replace it.

I watched a few YouTube videos about sealing up attics, but honestly, it seems like everyone has a different opinion on what's best. Spray foam, caulk, weatherstripping...ugh, it's overwhelming. And I'm not exactly handy, you know? Last thing I want is to spend a weekend crawling around up there only to make things worse (or fall through the ceiling, lol).

Has anyone else dealt with this? Is it worth trying to DIY or should I just bite the bullet and call someone who knows what they're doing?