No matter how bad someone has it, there are others who have it worse. Remembering that makes life a lot easier and allows you to take pleasure in the blessings you have been given.
An agent won't help you get drafted higher, won't make you win more games, and won't make you faster or stronger. They all say they can, but the people who do the drafting don't talk to agents. They talk to coaches, they watch film, they talk to the people who've worked with players. They don't talk to agents.
If you want to get a deal, negotiate with the teams yourself. Say, "I want this much, and no less, but I'll show up to camp on time." It doesn't seem that hard to me.
What you are capable of achieving is determined by your talent and ability. What you attempt to do is determined by your motivation. How well you do something is determined by your attitude.