This is quite a difficult one and nothing came to me at first, then after some deep thinking I came to the conclusion that you really had seen God in your dreams.
Firstly, you saw an old man with white hair. In Daniel 7:9, 13 and 22 God the Father is described as the Ancient of Days.
Then you saw the three balls of string. The first two show a long life and a short life. But the long life stretches into infinity and the short one is cut short by death.
The string which stretches out into infinity belongs to the person who inherits eternal life. Such a person may die in the body, but will not be affected by the 'second death' (Rev. 2:11; 21:8), for when the resurrection of believers comes, God will raise him up to eternal life.
Joh 11:25 Jesus said unto her, I am the resurrection, and the life: he that believeth in me, though he were dead, yet shall he live: and he that lives and believes in me shall never die.
Finally, we come to the third ball of string - you. It is within your choice, says God, whether you will choose eternal life or the second death. What is his requirement? You said it is something like being a good person/not doing bad things. You're not sure.
This is actually crucial, as to how God actually defines what a 'good person' is. Scripture says 'there is none righteous, no, not one' (Romans 3:10). No-one can get to heaven on his own righteousness. You'd better give up, right now, if you think you can make it by 'being good'.
A christian is one who has given up on his own righteousness to get him to heaven long ago. There is only one way, through Jesus Christ the righteous Son of God. Only he lived a sinless life and gave his life as an offering for our sins (ie. shortcomings). So, we can only get to God - ie. inherit eternal life - through trusting in the blood of Jesus, which alone makes us clean of our sins.
That's it, in a nutshell. Sorry if it sounds a bit relgious, but there's no other way of explaining how you can take hold of eternal life.
I have to say that this one is witnessing more and more with me that this is God speaking to you, telling you to choose, for you do not know how long your life will be. God does speak to people in dreams, and I cannot find any serious fault with these dreams which you have told me.
Regarding Jesus appearing before you in the toilet. This is harder. Maybe the toilet thing is referring to your humanness and therefore your own mortality.
Jesus didn't say anything, because he didn't need to. You know that this appearance was related to your previous dream. It was like a reminder. Make up your mind, he was saying, about me.
Ro 6:23 For the wages of sin is death; but the gift of God is eternal life through Jesus Christ our Lord.