Teeth movement after orthodontic treatment 7 years ago. What can I do? (Photo)

Hello. After having my braces off at 15 years old, I am now 22 and I stupidly haven't worn my retainers in about 1 year. My front teeth have started to move forward again (which was my problem before braces) and I'm kicking myself for not continuing to wear retainers. Is there anything that can be done to correct this before it gets worse? I have made an orthodontic appointment but I am anxious to know what he will say. Will this be expensive to correct? Thank you!!