I'm Catholic and have made all my sacraments. I'm going to Israel and am interested in being baptized in the Jordan River. Is this allowed?
No, you cannot be baptized twice. The sacrament is unique and irremovable, and there is therefore no need for a second baptism. According to the Code of Canon Law only unbaptized individuals are eligible for baptism:
Can. 864 Every unbaptised person, and only such a person, can be baptised.
The Catechism of the Catholic Church also quotes this canon directly:
1246 "Every person not yet baptized and only such a person is able to be baptized."46
If it is uncertain whether someone was baptized the Church may perform what is called a "conditional baptism," but this is very different from a second baptism such as you desire.