Finishing Seam on Thumb!

I am working on knitting my first pair of boucle mittens but am stuck on how to finish my thumb!
The instructions say:
“Next row: (K2tog) 7 times. Break yarn. Thread end through rem sts. Draw up and fasten securely. Sew thumb seam. With RS of work facing, join yarn to last st on right hand needle. Pick up and knit 2 sts at base of thumb. Knit across sts on left hand needle. 34 sts.”

So far I’ve K2tog 7 times but am entirely lost after that! I don’t understand how I’m supposed to sew the thumb seam after threading through the rem stitches and I am entirely lost on how to join to last st on right hand needle to knit sts at the base of the thumb…
Here is the link:

After you finish the decrease round (k2tog 7 times) cut the yarn leaving a good 12-15 inches. Thread the yarn through a tapestry needle and then put the needle through the remaining thumb sts and take them off the knitting needle. Gather the sts on the thread and pull fairly tightly. This’ll close up the top of the thumb. Yyou can make a small knot at the gather to secure the sts. Now you can use that same needle and yarn to stitch the seam down the thumb to close up the thumb and bring your yarn back to the base of the thumb. Tie it off here. You’re going to need to start with a new end of yarn. With the new end, pick up 2 sts at the base of the thumb (it’s now a tube) and then continue on with the sts on the other side of the mittens. You’re joining the palm and the back of the hand to each other again, with the completed thumb in-between.
Here’s a video that shows picking up sts.

Okay I managed to finish off the seam of the thumb back down to where the next set of stitches begins at the base, but now I’m confused about what to do after I get there /: I understand that I’m supposed to pick up & knit the first 2 stitches at the base, but I do not understand how I’m supposed to end up with 34 stitches on my needle when there are only 17 stitches remaining on the stitch holder… Am I supposed to increase the stitches that are remaining? Or am I misreading the directions and am I only working with the 2 stitches picked up & knitted to begin with?
Thank you for helping me!

The thumb is in the middle of your row. You have something like 17sts on each side of the thumb. With the knit side facing you and a new strand of yarn, pick up 2 new sts at the base of the thumb and continue to knit the sts which have been waiting while you knit the thumb. Turn and purl across all the sts to the end of the row. Now you’re going to work back and forth across all the sts (~34sts) until the given measurement for the hand.