It sounds like you might need a therapist. Sometimes anti-anxiety medication needs to be prescribed by a doctor in an emergency, but otherwise, I don't believe anybody should be on such medication without being under a therapist or psychiatrist's care.
If you find a good therapist, you might not need the meds. With Crohn's and without the support of parents, there are plenty of good reasons to be anxious. Learning how to manage anxiety is key.
A good psychiatrist might recommend some other anti-anxiety medication for about a month, such as Klonopin, while shifting you over to a medication like Lexapro, which takes longer to work. The goal of a good therapist should be to help you find your way to eventually manage anxiety without meds.
A good therapist would also help you determine whether pain medication is becoming a crutch or addiction.