Hi istahhcy,
I feel your pain. I have recently been on a "downswing" which lasted about 6 months. It seemed that no matter what I did, I couldn't win. My opponents just kept hitting their flushes, straights etc whilst my sets, straights etc never seemed to hold up. Not only on-line but live in the casino also. It really made me begin to question whether i could be a winning player.
The fact is that luck does play a part in the game and if you're getting your money in with the best of it and still losing there's not much you can do but reflect that you made correct decisions but just got unlucky...
If I didn't really love poker and most everything that comes with it I would have quit long ago after experiencing those nasty "downswings".
One of the first things I asked myself not so long ago when in the middle of this "downswing"
was - "Am I really on/in a downswing?" Meaning, am I just getting unlucky or am I doing something or some things wrong and if so what are they and how can I fix them.(I also noticed that I had begun putting a lot of things down to the "downswing" that could be changed)
With that in mind I really sat down and began to think about my play.
One of the first things I started to do was recording my poker sessions on an exel spreadsheet
Live/Online(different sites)/Tournaments/CashGames/Game type/Length/Comments
This really helps you to see exactly what youre spending/making/losing money and where
you're most profitable
It may be that you are playing a particular site/game because you enjoy the game/site/players but are actually losing there.. Try and concentrate on your strengths according to your stats.
Also. Don't fall in love with a particular table/time or site to play on unless youre profitable.
I played a lot on PStars last year and really hit a "downswing" towards the end of the year.
I spoke to a few people about it and they suggested a few other sites and also that I should move off a table if the play is very strong. He said "Its not like there's a shortage of other tables to choose from." Now, if I dont like the table, I leave immediately.
Regarding time to play. No doubt you have noticed the different styles of play of Scandinavians v's US players etc. If you record the times you play and record your results v's players from certain regions at times past midnight (where they are) you may find that that is a profitable time to play and make yourself a schedule of when you should log on.
There are also a number of good tracking programs that give you all kinds of information about your opponents. I am in the process of looking through these for myself so will post my results when I am finished.
I then asked myself - When is may game less than at its best and what can i do to recognize this?
1/ When I'm tired - Who has played for longer than they really shoud have and ended up making some less than perfect decisions?? ME!! I play at least 33% worse when i'm tired.
I now try to limit my sessions to 8 hours max and take appropiate breaks for meals etc.
2/ When I'm drunk...yes I have come home after a night out and logged on and tried to dominate the world and woken up the next day with a 0 balance.(these are the types of players you should be looking for)
I don't play after a night out any more. Well, maybe a little 
3/ When I'm stressed. Playing when there is anything else on your mind is not a good idea.
I play about 33% worse when thinking about anythying else either cosciously or unconsciously. Particilarly money. If you're worried about the money your game will faulter.
bankroll management is key. The articles on this site are very good and there are plenty of others about.
I dont play when i'm stressed or if I do I play low limits to limit potential losses
I only usually play with 3 buy ins behind me in cash games. I have found that if I lose 3 buy ins in any game then i am just having a bad day/night and should move on.
4/ Positive thinking. I think most people who have had a bit of bad luck know what it's like to
look at the board and expect the flush or straight card that their opponent needs to hit. Its easy to get negative and start playing that way. It only serves to perpetuate the "downswing".
I try to start fresh each day and play a positive game. I raise almost all my good hands. I don't just wait and hope to have the best hand at the end.
SO, ARE YOU REALLY ON A "DOWNSWING"? Maybe, but try a few of the above and see if things improve.
Wow, I've rambled on a little longer than i expected to...
Anyway.... I hoped this helped.
It definitely helped me. After doing all of the above and reading this sites educational articles I managed to turn the $50 sponsorship I recieved on FullTilt into $550 in 1 week.
Good luck at the tables!