No return offer with 2 weeks left in internship

Ending my internship in less than 2 weeks. My manager has said he doesn’t have any full time reqs available for me at this time. This has been kind of disappointing, considering I was under the impression for months that I had the offer in the bag. My performance reviews were all decent. He seemed to imply I was doing a good job. He’s encouraged me to reach out to managers in adjacent departments and network. I’ve reached out to several and get ghosted each time.

Honestly I’m a bit nervous right now. I graduate next summer and do NOT want to be scrambling for a job after graduation. I’m so mentally exhausted from the job search process in general. I’m tired of being a student. I’m tired of being financially insecure. I KNOW I’m competent enough to work full time. I KNOW I can handle the work and am smart enough. I’m ready to transition to this new stage of my life but just feel so lost in navigating the corporate world. It feels like nothing I do will ever make me good enough. It feels like hard work doesn’t truly lead to success. It feels more like a question of whether or not you “fit” into the “culture” of a particular company.

What should I be doing right now?! Should I follow up with the managers that ghosted me?! Are there any networking hacks or tips I should know about?! I’ve been applying to positions internally and planning to spend my remaining time networking. I don’t know what else to do and just feel lost. Senior in SE.