Getting off anti-depressant?

I have been on celexa generic for about two years. It has helped me alot with my anxiety. I feel that I much better. My doctor told me to cut my 20mg pills in half and take 10mg once a day for two weeks and the thrid week one every other day. I am almost done with my 2nd week. I have noticed that i have been really emotional. I cannot figure out if it is because i now have my period, or its me withdrawing. I have a doc appt in 4 weeks ( 3 weeks after i am off meds) I have also noticed that i have a low sex drive. It has been that way for a year now. I thought it was the antidepressant. I am also taking Sprintec( birth control). Has anyone else had the same problem getting off antidepressant? I also have been getting headaches. Me and my bf are fighting because of my low sex drive and because of me being too emotional. I cant help i just want to cry. Please help.