Got a third in my second year, can I still get a 2:1 overall?

Hello, hope everyone is well. I'm going into my final year of Economics at UCL. I've been slacking off and my grades aren't as good as they should have been, put in next to no effort, and could probably count on two hands the number of lectures I attended in my second year, and first year as well to be honest.

First year is weighted 1/9,
Second year 3/9, and
Third year 5/9.

Got 60.705% in my first year, 49.666667 in my second, and of course am about to begin my third year. To get 60% exactly, which I believe gets me a 2:1, I would need 66.059% (Also I'm only counting my best 90 credits from years 1 and 2, as this is what believe is how we are graded).

Even though this will be extremely difficult, I believe I'm committed to doing what it takes to get it, attending every lecture and seminar, all the office hours and extra reading. With the little work I did in my first two years, I think it's possible for me to get the 2:1.

I was just wondering, firstly, could someone check if what I've said is correct, I believe it is, but I'd like to be sure of what I need to do. I'd also like to see if anyone has any tips or any advice on what I could do to help make my 2:1 possible. Some encouragement would also be appreciated. Thanks for reading.