Hey that's great man, but I'll be honest with you- you shouldn't see those as exceptional improvments! If you are training the right way, you should be expecting those kind of improvements every cycle! You should now be seeing how important regulating your volume is.
At this point, I would actually make some slight changes to your program and I think you will see some good results with the changes.
One thing that you should probably do at this point is oscillatory isometrics (OI's). They are kind of tricky to explain, but pretty easy once you start doing them. I'll explain how to do OI bench press.
-Hold the weight (start with 30-40% of your 1RM) a little short of lockout.
-Totally relax your muscles and let the bar drop towards your chest.
-As the bar crosses your sticking point (the point where you usually fail at the lift, probably about 6" off your chest) immediately engage full tension in your muscles and snap it back up.
-As the bar crosses the sticking point again relax your muscles and let it fall (don't pull the bar back towards you, just relax your muscles) and repeat.
You should think less of doing reps and more of using the stretch reflex to snap it right up through the sticking point, then allowing your muscles to relax again. When you are doing it right, it should feel effortless, at least in the beginning until fatigue sets in.
As your muscles get more tired you will have to be more efficient in using the reflex to snap the bar back up instead of muscling the lift. It's also important to limit your range of motion to about a foot or so. Don't think of it as speed reps, just think about cycling just over and just below your sticking point as rapidly as possible.
Basically OI's perform two main functions:
1.) They serve as "sticking point theraphy." That is, they improve your strength in a very specific area- the one that you are weakest in, while still maintaining or even improving your reactive ability. In that reactivity sense, they are superior to traditional isometric training.
2.) They are very good for short-term hypertrophy. Putting on mass will definitly help you in this competition and these will help you back on some mass to your triceps and chest.
With that said, think about doing some slight changes to your program. You said you are 3.5 weeks through, so I'm assuming after your complete this week, you will have 4 more weeks to train for this competition? I'm going to assume that's the case and give you a little redesign that you might want to check out.
For the next three weeks, try this:
A. OI Bench Press
Do as many "reps" (or cycles past your sticking point) as you can in 40 seconds.
-rest 3 minutes-
B. OI Decline Chest Flyes (or flat chest flyes if can't get a decline bench)
Do as many "reps" as you can in 40 seconds.
-rest 3 minutes-
Continue repeating this cycle until you can only hit about 90% of your reps in the OI bench. So if you hit 60 reps the first time, keep going through this rotation until you can't get 54. Usually there will be a pretty sharp drop-off on this, so if you get 52 or 53 (using the hypothetical 60-rep benchmark) do another rotation.
Again, do a hard, but not maximal 5x5 on squat or deadlift, but be sure to not hit failure. After this, do a trap/delt superset.
A1. Shrugs or Close-Grip cable rows to your neck.
A2. Front or Lateral Raises.
Do 3 or 4 sets of 8-12 of each of these exercises with 2-3 minutes of rest. This is not that vital, so don't kill yourself on this superset, you just want to add a little bit of strength to your traps and delts.
A. Close-Grip Bench Press
Work up to a 5RM. You'll do your remaining sets with 15-20 pounds less on the bar.
-rest 3 minutes-
B. Standard Iso's
Hold your 10RM at your sticking point for 30 seconds.
-rest 3 minutes and continue until you can no longer get 5 reps on your close-grip with 15-20 pounds less.-
Just makes sure you have a spotter so you don't have to press the bar back up after the iso's.
Over the next 3 weeks really make sure you're really eating plenty of food, 2-3 pounds of extra muscle gain between now and the contest could be the difference!