It breaks my heart beyond belief to see any of my friends unhappy or hurting. Especially when the hurting is being caused by the last person who is supposed to. I know that advice is much easier to give, than to actually use and put into practice.
You are responsible for your own happiness. You are a completely wonderful person, and whomever you decide to give your heart to -- should forever be grateful for it. You're worth a phone call. You're worth the time, YOU ARE THAT IMPORTANT. The person you are with should respect and love you enough to make you feel completely wonderful. If they can't give you that which you deserve, there IS someone out there who will. PLEASE, never settle for less than you deserve. Never settle. Realize that if you are not happy, something is not right -- it's not okay. Don't be afraid of failure. Yes, you worked hard to get where you are, you worked hard for this person to be in your life, you've done so much together -- things don't always end up panning out the way we planned, it's okay to let go. Any situation that you find yourself in, you are responsible for it, you are capable of fixing it, improving upon it, taking steps to make YOURSELF happy. Life is too short to be anything but happy. You're deserve happiness.