Well, the clear fluid may not be ejaculate at all. It may pre-ejaculatory fluid which many men produce. See
http://en.wikipedia.org/wiki/Pre-ejaculate for a little more information.If it is ejaculate, remember sometimes it can be clear, runny, yellowish, thick. There could be lots or a little. Ejaculate production can be influenced by many things. As for loosing an erection, that can be down to stress or many other physiological issues. However, if you are very concerned about this, I would always recommend seeing a doctor as it is very possible that there is a physical reason for sexual performance. Hope I have helped.