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The amount of the debt doesn't affect your score. It could affect you applying for credit though if your DTI is high.
If your DTI is, lets just say, $300 and that is 25%; that means your total gross income is about $1200 per month.
You can do two things: 1) increase your income or 2) pay off the debt or 3) a combination of the above.
If your income really is $1200/month than it would be easier to increase your income. That will also give you extra funds to accelerate savings and payoff of your student loans. You don't say what the interest rate is on your student loans, but at $300/month and a $45k balance you are in it for the long term unless you can accelerate your payoff.
DTI = monthly debt payments divided by your gross monthly income.