Go to community college, get your pre-reqs out of the way.
Avoid credit cards if you can. You have little means to pay them off (in full) so there is no point in having them and tempting yourself.
Find your passion... then figure out whether you can make money doing that and how likely you will get a job doing it. If you can't, find something else and do your passion as a side-job.
Don't go for an Art History major because very few jobs 'require' it and the ones that do are few (How many art museums in the world are there and how big is the turnover? Not very many and most likely not very much)
If you make like $1000 per month, $100 / month investing is 10% of your income. When you graduate, you will be making let's say twice that (to be conservative), well now that $100 / month is 5% of your income which gives you a bigger margin for living.
This isn't to say "Blow all your money". This is to say, don't worry about scraping together pennies when you will be able to fund it better in the future.
Yes, having older investment gives bigger returns, blah blah. But three or four years aren't going to kill you or doom you to poverty (regardless of "lost returns")
Learn to budget. Give every dollar a job. Buy YNAB. Budgeting will remove a lot of stress from your life.
SAVE MONEY. Open a savings account and put some amount of your savings account and then forget about it, which you seem to be doing well.
Don't become obsessed with saving a stupid amount of your money. You are young, make mistakes. Regardless of your age, don't become a curmudgeon just to say you have $X in the bank. Money doesn't make you any happier, maybe just slightly more comfortable