You have to realize that the severity and time span of your acne is already predetermined. Maybe your skin will be finished with acne by 22~23, and you are still just 16... I spoke with a dermatologist about acne and he said the trend is that of a bell-shaped curve. Meaning when you first start it is at it's lowest (fewest pimples, least severe, longest time in-between break-outs) and also at the end of this curve when you are older it is lowest (before it stops altogether). The time after you start will just get worse and worse until it hits some peak (which may not be so bad, or it might be terrible... everybody is different) and then it will gradually subside until it ends. Now, you also have to consider that not every bell-shaped curve has perfect symmetry... You may not peak until the end and then have a rapid drop-off and then your skin will be fine... or it could be a rapid worsening with a gradual roll-off... For me I had a gradual worsening with periods of ups and downs (which is what I think you are experiencing) and I'll explain why.
Antibiotics are a temporary fix, and the reason is because the bacteria which the antibiotics are meant to combat eventually develop a sort of resistance to the drug(s). This is through a natural evolution, and you'll notice your derm will put you on antibiotic A for a few months or so until your acne stops responding, then you go onto antibiotic B for a few months until your acne stops responding again. At this point you could either move on to antibiotic C or go back to antibiotic A. There are a bunch of reasons why he'd opt to put you back on A or move on to C... but it's not overly important right now.
Understanding about antibiotics, we can now look at how it fits into that parabolic trend of acne you will experience through your adolescent years. While you may think antibiotics will somehow be taking control of your "fate", they are really only minimizing the effects for a short duration of time, then you jump back up to where you would have been without the antibiotics. So that gradual worsening doesn't happen because the antibiotics were there, but now you pick right up wherever you should be on that curve, and that creates this misconception that antibiotics only work for a little bit and then end up making your acne worse. It just isn't that way. Antibiotics work, but they do a number on your gastrointestinal tract and personally I hate them because they always make me feel like crap. Plus you can only take them with meals... Blah. I had the best luck with Accutane (it's the only thing that worked to this degree... otherwise benzoyl peroxide worked really nicely but not quite like Accutane). I definitely recommend Accutane ONLY after you've tried at least a dozen other products from your derm without success, done your research on the drug, talk to your derm about it, and really think it over. It's a great drug but there is so much involved with it you can't be blind when taking them. Ignorance could kill you (literally in this case).
Anyway, I just wanted to make it clear that your body runs on it's own tracks, and it's going to do what it's going to do. All you can do is try to minimize the bad but whatever you do don't give up hope.
I hope this post was helpful.