The web is awash with guides with titles like "How to get your man back!" or "Make her love you again!" They cater to the desperate and despairing. According to Google, literally millions of people search every month for guidance on getting partners, boyfriends and girlfriends back and repairing a broken relationship.
If you are one of those people, firstly I'm sorry for your suffering, secondly there is a way forward, thirdly the majority of 'save my relationship' guides out there probably aren't going to help you.
If you're suddenly without the company or connection of someone you love deeply or have depended on in some way to meet your emotional needs, it's understandable that you might be feeling desperate for things to return to how they were. But if that's the case, there's something you would do well to do before worrying about getting back with anyone.