What happens when someone with a chemical imbalance comes off their medication?

I've been on anti-depressants (Effexor a.k.a Venlafaxine) for well over a year now. When I was taking them regularly I was so many times happier than without them, but I could never really attest whether it was attributable to the tablets, or whether my life was better once I left university. For the past month, I've been cutting down my dosage from 150mg > 75mg > 75mg every 2 days > whenever I feel I need a tablet. My aunt said to me tonight that she's worried about me and that I have been more angry, depressed, unhappy, paranoid etc but we can't tell whether its the absence of medication or just life. Recently, I've been going through a lot... I'm struggling financially, the government is trying to take my support away, I've fallen out with a group of people who hate me now, I'm really lonely etc. So I'm wondering, does a chemical imbalance ever get corrected through anti-depressants or will it still be there once you stop taking them, like one person jumping off from one end of a see-saw? Thank You, M