The English word angst, taken from German Angst, seems to ultimately originate from Proto-Germanic *angustiz. This word has descendants in many Germanic languages, including, but not limited to, Danish, Norwegian, Swedish, German and Dutch. The English word anger is also related to this group.
The English word anxiety has a similar meaning and seems to derive from Latin anxietās. This word has cognates all over the Romance languages, including, but not limited to, French, Italian, Spanish and Portuguese.
These two groups of cognates mean similar things. If we go even further back, is there a link between the two groups, for example in Proto Indo European?
I would prefer if answers included a source.