Your current income is king here. In my opinion, no need for a joint sponsor. Your AGI is not the number shown on the I-134 though. While the number is often the same, you use the "total income" not AGI. For current income, state your current income of way over 100k. Calculate it using gross pay for a full pay period, times the number of pay periods in a whole year. Add those two figures together and that is your current income. Document it with the copies of the pay stubs you used to calculate it.
Once you file to adjust status, you do the same. Perhaps you will have filed a new tax return by then.
"Joint sponsor" takes about two seconds for me to type, but securing one, asking them to disclose the information, then complete and sign an I-134 is a much bigger deal. Even a bigger deal for the binding I-864. Expect success based on your actual current income.