Is what happened considered a severance of kinship ties, and am I sinful for not knowing my relatives? And how can I maintain kinship ties, mentioning their virtues and the punishment for severing them?

The Wise Lawgiver (Allah) commanded the upholding of kinship ties and promised a good reward for it, while condemning its severance and threatening those who sever it with punishment. As it is stated in the Hadith: "The one who severs the ties of kinship will not enter Paradise." The true meaning of upholding kinship ties is to reconnect with relatives if ties have been severed. If you are able to connect with your relatives directly or via phone and you do not, then you are a severer of kinship ties. However, if you are unable to reach them by any means, then you are not considered a severer of kinship ties, because "Allah does not burden a soul beyond its capacity." It is obligatory to observe the Sharia guidelines when connecting with female cousins with whom you do not have a prohibitory degree of kinship (mahramiyyah).