Need some help

Recently got sober the past few days and feeling a lot of anxiety and grief about getting sober. I’m already feeling like relapsing I have so much anxiety and worried about how I will stay sober during cravings. I’m on the way to my methadone clinic as we speak and I’m so worried my dose won’t hold me and I’ll end up wanting to use again ( haven’t tried to see how long my dose would last me for without using ) Just need some encouragement I guess :/