Okay, first off, remember that rumours are just rumours - people forget about them when something better comes along, so I don't think they're anything you need to get too worried about. Everyone gets gossip spread about them at some point or another, whether it's good or bad, true or false, and it's just something you need to ignore. However, even though your friends didn't understand your obsession with this guy, it's not a reason to lie to them. Do they know that you were lying yet, or have you told them the truth? If you haven't, I think you need to talk to them. Lying isn't good and part of you is probably still feeling guilty for it.
But, moving onto the situation with this guy, I think it's important you try and talk to him and tell him your feelings. I realise this is pretty much impossible to do in person, so I'd suggest you write him a letter and find a way to give it to him, and make sure he reads it. I think it's important that he knows how you really feel, gossip and rumours aside.
His unrequited love is probably a huge part of your depression, but I'm sure there are other factors involved. Being on medication is definitely a step towards getting better, but have you considered some form of therapy? It sounds like you really need somebody you can talk to openly, without being judged, and I think that therapy might be one way you can do this.
I hope things work out for you, good luck!