Am I screwed if I don't have an offer for SA 2019?

No you aren't screwed. This site is filled with complete misinformation from kids who once they reach an actual intense job will realize two certainties: 1) the world isn't zero-sum 2) if you have sharp elbows and try to harm others to reach the top, intense team players will recognize your behavior and ensure you do not get employed at firms with healthy culture and good results. Finance is small and people have long memories.

Several bulge brackets are still recruiting, several boutique banks are, some also are finished (mainly smaller offices). Additionally, if you don't get a SA at a BB bank you can try for a regional bank and recruit for a full time position anywhere you want (read a real offer, not a internship). If that doesn't work you could try to possibly recruit for consulting and you might even find you enjoy it better, or possibly you could source this summer at a MM PE shop and they might even hire you. You could even be in a different industry, go to business school, and recruit for an associate position. The bottom line is there are just so many ways to skin the cat and you aren't screwed if you don't have a summer internship. Life is a marathon not a sprint and if your goal is to end up at a large PE shop or large bank there are so many ways to get there assuming a 50 year career. I'm assuming many of your friends have offers and that is great, but also here's an unfortunate secret: the job recruiting process never ends. It is a street fight from now until you stop working, so embrace it. Also, for the kids that think a SA position will set them for life, they are so wrong. The amount of friends I have watched have a quarter life crisis at 25-29 because they realize they don't know what to do after banking or PE is over is unbelievable. Envision your ideal job 10-15 years down the line and try to acquire experience for that job. In the scheme of things, your SA position is just not that big of a deal. Keep your head up, define your own values and the job YOU want, and work hard to pursue them and you will be fine.