hCG during cycle - This will help keep your producing some TSH and will for sure help you in your PCT since this is already in your system.

Are you going to fuck anything for life? - There is always the possibility of ED issues after any cycle, however this is easily remediated. In fact, people without major ED issues but minor still use a pill to bring the absolute A game when the time comes. I would not worry too much about this since prices for the medications are already cheap, hardly if ever faked (although QA can be tricky, but mostly over dosed and not under).

Test C - This is a tricky one. Testosterone C has a cyclopentylpropionate ester (8 carbons, ring structure). The recent studies show the ring stucture can break off more unpredictably than Testosterone E which has a heptanoate ester (7 carbons, straight chain). Testosterone Cypionate was developed by Upjohn Laboratories (U.S.) in the 1950s. It was one of the first long-ester testosterones approved by the FDA, and because it was made domestically, it quickly became the U.S. standard. Test E on the other hand, was synthesized and marketed primarily by Schering AG (Germany) around the same time, gaining traction in Europe, Asia, and the Middle East instead. Test E is showing, as of this post, a more predictable release schedule, but things could change as further studies are shown. Honestly, this is diving into the weeds and I wouldn't worry too much about it.

My final tweak would be start PCT 14 days after your last testosterone injection with Nolvadex at 40mg per day for 2 weeks, then 20mg per day for 2 more weeks (optional: add Clomid at 50mg per day for the first 2 weeks and 25mg per day for the last 2 weeks for a stronger restart).

You’re 21. Don’t do steroids now. Yes you will fuck your natural test production. At your age you should have more than enough testosterone to hit the gym hard for next 10 years and make great natty gains before jumping on test.