The only risks for HIV in adults are:
1) Having unprotected (no condom) penetrative anal or vaginal sex, OR
2) Sharing IV drug equipment with other IV drug users.
Yesterday, you were sure you got swollen lymph nodes from a no-risk event with a stranger a month ago, and now you think the nodes, which have been present for several weeks, were caused by no-risk oral sex that you and your (new?) boyfriend gave to a stranger last week. That doesn't even make sense.
I don't know what you mean by "gave something to each other." You can't spontaneously give a disease to each other that neither of you has. Only one person can infect another person.
In any case, you haven't had a risk for HIV, and if your nodes are giving you anxiety, get them checked out by a doctor. Also, if having sexual encounters with strangers/people of unknown status gives you this level of anxiety, you should consider not engaging in that activity.