Agreed with gf here, no way you are at 4% body fat absolutely no way...
Drop the deca as mentioned before and don't dose test every 10 days your blood levels will be like a rollercoaster which leads to side effects.
Wouldn't reccomend 250mg pw personally I think it would be a waste of time since at your age your body is probably making 60-80mg pw, take off the ester weight of the test e which is 30% ish and your left with round about 175mg test and that's assuming your using pharma grade gear and not underdosed ugl gear.
I mean it's still an increase of around x2 or slightly more actual test but if your going to shut your hpta down you might as well make the most of it without going crazy.
If wanting to keep dosages down how about even .75 x2 per week = 375mg.
Why 250pw GF, seems quite low even if he weighs quite little, and if he is anywhere near correct even by a margin of +5%., most of that is muscle mass?
Just my opinion though but I really think you should know what your doing op before injecting yourself with powerful hormones...
Have you got a pct?