It happens sometimes. People you thought were down for the trials and tribulations on your path to success disappear, but when things are looking better they don't make the return you thought they would. It's NOT your problem and here's why.
They Already Counted You Out
Not to say they weren't wishing the best for you, they just thought it would happen sooner. When it didn't, they shifted their attention to the next "big thing". Since they dropped out while you were on your way up, it's easier to pretend they don't see what's happening with your career now.
Were you counted out too soon?: Don't sweat it. People are bombarded with a lot of things on a daily basis. It's natural for them to attempt to weed things out to focus their attention on the things that matter most to them. Don't take it personal, check in with your friends on a personal level without the motive of promoting your new artistic endeavors and see how they're doing, after all they're human, not solely customers so you should be doing that anyway.
Did you count someone out too soon?: It happens, it's easy to categorize stuff to make things simple. If it's a relationship you feel is worth salvaging, reach out and see if there's anything they need you to do; whether it's previewing new material, sharing it with friends, etc...just reach out selflessly without a motive...it'll go a long way.
Your Success Reminds Them of Personal Goals They Didn't Accomplish
It's easy to celebrate others when you're confident with what you've achieved, but when you're struggling with benchmarks you haven't attained others reaching theirs causes you to reflect on what you feel you have left to obtain.
Have people felt bad because of your recent success? It's not your fault. You worked hard to get where you are and you were blessed with opportunities you should not feel guilty about. It's up to those who are resentful to come to terms with what they are feeling. Stay on your designated path.
Have you felt bad because of someone's recent success? Figure out what's really happening with you. What would cause you to not want to celebrate the success of a colleague? If you feel bad because they've done something that you wanted to, but haven't yet it's not their fault. Evaluate your objectives. Plan a path to obtain the goals you wish to and utilize your contact(s) as a resource since they've already blazed the trail. Try your best not to burn bridges by ignoring the opportunity to connect.
They Weren't Really Friends from the Start
Sometimes people forge connections based on what they feel you can do for them. Some are really good at pretending they want what's best for you, but can grow frustrated when it doesn't benefit them in the way they initially thought it would.
Have you lost faux friends? Don't worry about it. You don't need people on your team who aren't rooting for you to win. Stay focused on your goals and the people around you who actually care for you and want you to succeed. The best revenge is simply being happy.
Have you been a faux friend? Evaluate ways to achieve your goals without relying on someone else's success. As opposed to being envious of someone reaching their goals before you did, pay attention to how they accomplished them and apply some of those principles to your endeavors. There's room at the table for everyone to eat, there's no need to let jealousy burn bridges and get in the way of achieving your passion.