If you have applied for 400-500 jobs and haven't gotten any interest at all, you need to find an independent editor to review your resume and, more importantly, your clips. Many SEs may read one paragraph of a clip and toss your resume out. Or just look at your resume see a small typo and throw it out.
As for no job a few months out of college, to me it's funny how much the younger generation thinks the degree automatically means a good job. It just ain't the way it is, especially in sports journalism. Companies are cutting back staff left and right, and the jobs you apply are being filled by the Joe Blows with 10-15 years experience, because for every fresh out of college guy out there looking to get in this field there 3 Joe Blows looking to find employment.
I'll tell yo my career path: I took a job as an obit clerk. Did that for about a year. Added on some sports clerk stuff (mainly track agate...fun) then got a job opening at a major metro for a part-time phone/agate clerk. It was pure grunt work, the pay sucked, but after a year, I sent out my resume to three companies. All three called for interviews, I interviewed all thee places, one called the day after the interview and offered a full time sports writing job. The other two called later that week and offered. The only clips I had were still from college, but the grunt work was enough for these three. Sever decades, a few dozen SE and MEs and 100s of coworkers later and I'm still in this biz.