It's not all lost. There are plenty of companies that accept graduates with 2:2s and some don't even state any grade requirements. The main thing when it comes to job searching is to keep an open mind. Use as many job boards as you can to find opportunities. Some of the best ones i've used were indeed, reed, cvlibrary and gradcracker. Also, don't forget to use your university's career site because it may also provide some opportunities. As long as you keep an open mind, polish your CV and nail the interview technique your degree will have almost zero weighing.
In reality, your degree is only used for the initial screening and only forms a small part of your application process. It's definitely possible to find a role even if you had underperformed at uni. Since you finished a computing degree, you can do a lot with it. Most entry-level or junior tech roles will be open to you. Maybe you would be interested in software engineering, DevOps or data engineering? There are also many IT roles that don't require degrees. So there are plenty of opportunities and keep looking and make the most out of the chances that you're given. You can't be too picky about your first job. Even if it's a slightly lower level IT role, it could still provide you with valuable experience and you could move up the ladder. The hardest thing is to get your foot in the door as they say.