Elana,
I've taken Celexa for several years now. I too has the side effect you did. Mine did go away around a month into it. Hang in there with meds. If they don't work go back and see if they can increase your dose or try something else. 15mg is a very low does (I take 80mg on top of 300mg wellbutrin.)
Another thing, well question really. Do have just depression or do have other disorders, major depression relaps, PTSD, BPD, bipolar. Sometimes you will be diagnosis with just depression but you may also have another disorder on top of it. I was diagnosised with depression, then Major depresson relaps, and finally I was diagnosed with BPD which has all the symptons of depression just more.
A good train pdoc would be able to help you with this. It make take several pdocs to find the right on. It did for me. Now with the right meds and right pdoc I am doing so much better. I hope this can happen for you.
You may just have depresion and need the right meds too. Get a good pdoc and T. They can help you.
Take care.