Hi. Friendships can last through sobriety but it really depends on the friendship. I have two friends who have stuck with me through thick and thin, sober or not but I've known these two women since we were 13 before any of us ever drank. They know I can't drink and it never comes up.
If the friendship is one that revolves around drinking or going to pubs to be social, then these might not last and actually, once you have sober time, you probably won't miss them all too much. At least that is what I've found.
If you really don't want to face dinner and drinks tonight because you might be tempted, call with your regrets and don't go. It's just one night. Maybe make plans with these people for an alternate activity like coffee, breakfast or lunch as people don't tend to drink at lunch that much anymore.
Most people like to socialize and get lonely if they don't. It does sometimes feel very isolating to be the person who doesn't drink but really, there are a lot of people out there who don't drink for whatever reason. We just don't see it because we are looking for what we want and can't have instead of what is staring at us in the face. If there was one bottle of beer sitting among a thousand bottles of water we would only see the beer.
Hang in there.