kaiWalk makes several good points - I think more detail is needed for more detailed answers.
But I can at least answer your question very generally. I haven't been playing poker (live or online) that long, but I have never made a deposit in online poker. This is of course a different way of approaching things.
My initial line of thinking was because a lot of online poker rooms have freerolls
, I wouldn't have to make a deposit. Then, I started to wonder, should I make a deposit even though I can't constantly win?
My answer was no - I know that freerolls are played differently because early on there are a lot of unsubstantive plays made (constant all ins and hyperaggressive betting) but how could I justify making a deposit if I can't beat the weaker players? (not necessarily criticizing you or anyone, btw)
I figured, until I could start playing well in freerolls (and subsequently in low stakes tournaments) I shouldn't make a deposit. I've stuck to this idea and have, I think, made improvements in my game - now I play in low stakes tourneys even though I haven't made a deposit.
And again, just a general response to your other question - I do think online poker is different from live poker. You can't see the person playing behind the computer screen - you can look into betting patterns and tendencies, but you may not be able to pick up a tell as you would in live play. Also online poker is much faster than live play so that can factor in - you may unknowingly be playing the game differently because the pace is different from what you're used to.
So many things factor in, but the good thing is, this is a great forum and I'm sure you'll learn a lot. Keep a positive outlook, reflect on your poker play and chances are, you'll turn things around.