1. Redo the vapor barrier on the ground, 8mil+ visquine works
2. Buy a spray foam gun and some cans of foam, about $70, and spray those rim joists. That is where your outside air is entering the crawlspace. Spray all 4 sides, especially where the rim joist contacts the sill plate (this can be a tricky spot, buy the professional spray gun)
3. Use the spray foam to glue the edges of your vapor barrier to the wall, let that foam cure for about 30 seconds before you stick the barrier to the wall, for maximum stickiness
4. Use that spray foam gun you bought to “glue” blanket insulation sheets to your crawlspace walls. I recommend the “all season” foam or something with good adhesive properties. We found the best way to do this is spray the foam all over the insulation, let it cure for about 30 seconds, and then stick it to the wall. If you stick it to the wall right away the foam might just feel off and you wont get a good bond

Source: I work for an insulation contractor and have been doing this daily for 2 years now