I'm not hot on the idea of spending fun money when you have credit card debt. I would do the debt first, but work some kind of job so you can pay off the debt without dipping extra-deep into your retirement funds.
And it does not seem likely that a college education would lead to seriously higher future income, so this is mostly for your own entertainment and personal growth. Assuming you have enough funds to afford to do that, then,
You are subject to regular income tax on the 403b withdrawal, plus a 10% penalty. You don't pay the penalty if you are over age 59-1/2, or if you stopped working for the plan sponsor in the year you turned 55 or older. So that extra 10% is going to hit you unless you just recently quit your academic job.
Your investments are subject to capital gains tax but only on the difference between what you originally invested and the value today, not the entire proceeds, and capital gains tax is lower than regular income tax as long as you held the investments more than 1 year.
So you will almost certainly pay less tax by cashing in your investments. I can't think of any reason to prefer to withdraw money from the 403b, unless you are expecting to die soon. If you died suddenly, your heirs would pay income tax when they withdraw from the 403b, but they won't pay tax (or only very little) if they cashed in the investment account, due to the effect of the stepped up basis.
