You've used 19 exclamation points in 2 posts. That's a ratio of 8.5 per post. If you never use another, I think the world would be a better place.
To answer your question, you are a little younger than I would recommend starting steroid use, but the chances of you recovering just fine are pretty good. Just finish your cycle, while taking an AI and hCG the whole time, and do a proper PCT, and you should be fine.
By 4 weeks you should already be seeing your strength increase, but you won't notice a big difference until 6-8 weeks. You're 20, you probably already have very high testosterone, and may not notice a huge difference except for strength and size gain, but that doesn't happen overnight.