Ok, I have the solution. I don't want to toot my own horn but in this case I will!
I'm just finishing up my 5th cycle which was 100mg of Virormone EOD for 8 weeks. Thats all! Less test than you're doing now...I'm up 10lb. and I'm mid way through week 7 (and this is a "cutting cycle"). Have low cals considering I weigh 290lb.
BACT TO YOU!
-Check your training first and foremost. Train heavy, basic compound movements. Try and build some functional strength.
-Did you get sick when you experience weight loss? that could be the reason.
-Vitamins are very important while on a cycle. Take them!
-Drink plenty of water
-Sleep
-If your intentions are to "bulk up" then cut back on your cardio, don't neglect it, but ease up on it.
These are some crucial factors that can affect your cycle. And don't listen to the guys that say in order to gain you have to keep adding more drugs, thats just bullshit. Everyone is different. I'm not saying I have all the answers, but as far as Test Prop Only cycles, I'd like to think of myself as advanced in this genre of cycling.
Hope this helps.
MC64