Even though your think your diet is bulletproof it clearly isnt because your bf is 20%. Starting steroids with an high bf can lead to increased sides. Fat cell receptors have more of an affinity to aromatising so if you have more fat cells ie more bf than you have more of a chance to increased estrogen related sides. Usually poor diet is related to higher bf % so this needs addressing first before steroids are used, especially if it increases side effects. Head over to the diet section and post your diet and see if we can help you out.