The unknown is filled with anything you want it to be. There's no reason AT ALL to think that letting go of something that is unhealthy for you will leave you sad, alone and regretful.
The Universe by it's very nature wants you to succeed! ALL THE GOOD STUFF is waiting for you to let go of your suffering, your insecurities and ANYTHING that doesn't match your best life.
When you let go of what isn't good for you - you FINALLY create enough room for what IS good for you to show up! Let go! Step into that unknown and expect the best!