Hang in there, Trix. I work with a team of 8... 5 SLPs and 3 SLP-As, myself included. I have been squirreling out the SLPs' grad school stories lately, and I have found that nearly every single one experienced some rejections and disappointments before the right door opened. One of them applied to TWUs (non-TETN) grad program straight out of undergrad, with a 3.1 GPA, and didn't get in. She worked as an assistant for a few years, tried again, and got in. She's now an SLP. I told you the story of my other SLP friend above, who got into the TETN program the second time around. The ones who did get into grad school straight from undergrad said that those with work experience really had a leg up over those that did not, and they fought a bit of an uphill battle there in the beginning.
This is just a bump in the road to you being an amazing SLP, and someday, your story will encourage others. It's not over. It's just beginning. You've got this.