Is it possible to lose copyright protection in my works?
Generally, it is unlikely that you could lose copyright protection in your protectable works without your active participation. Eventually, your works will move into the Public Domain, but at that point YOU won't be losing rights, you'll be dead.
You may assign permanently or on a temporary basis some or all of your exclusive rights to another party. Similarly, you may share those rights with another party. But in both cases, a contract is usually required.
Nevertheless, it is possible to lose "control" of your rights or let your creations languish by neglecting them. For example, if you freely distribute them publicly without some licensing mechanism you will find it hard to regain the control even though you have the same copyright protection you always had. Alternatively, a creation that is not shared by publishing or distribution of some type is almost non-existant and serves not purpose.