It's hard to say anything definitive without lab work. One possibility is that you are still getting fairly high peak testosterone. Even with a typical absorption rate, cypionate injected twice-weekly can result in serum testosterone peaks that are 50% over the troughs. For example, on that protocol I would expect my peak testosterone to be around 900 ng/dL with a trough around 600. If your physiology is attuned to a daily peak of 500 ng/dL then forcing it to 900 could indeed cause problems. On the other hand, your clearance rate for testosterone is likely to be higher than mine, so the numbers may not be as dramatic. Bottom line: get some lab work done so you can see what's going on. At a minimum measure total testosterone, estradiol and SHBG. Measuring free testosterone by equilibrium dialysis is also a good idea.
It may make sense to try spreading out the dose by injecting 3, 3.5 or 7 times a week. The more often you inject, the smaller the testosterone peaks.
