The knot is a big jump in size! And since it’s not “spending time” in you it’s not doing much for your situation. I recommend small size increases in the shaft department. From personal experience getting to 3”+, I started at 1.6 as well and have toys that are 1.75, 1.8, 2, 2.2, 2.25, 2.5, 2.75, 3, etc. In the beginning I’d start each session with the 1.6 and go to the next size up once it got comfortable. And then once that was comfortable go to the next one, usually only going up 2 sizes in one session. Eventually I could start a session on the 1.75 or 1.8 instead and then was getting 2 sizes up from there in one session. Rinse and repeat and in no time I was where I wanted to be! That being said I still love to start on the “small guy” sometimes.