Sensations in head while meditating?

So I haven't really meditated this intensely ever before. I usually don't meditate and I'm not a very spiritual person either but today was shivratri so I decided to just focus on shiv ji by chanting mantras with my eyes closed but slowly I could feel myself enter deeper and deeper into this state where I was concentrating on the mantras and not everything around me, usually I'm very mindful of physicalities while meditating. Then slowly I could feel myself entering this state where I went beyond the mantras also (at this point I played some mantras on my earphones and I was sitting in sukhasana with my hands in jnana mudra) and I could feel myself entering that state more and more and I felt some weird sort of ecstasy? And I feel like I was visualising? Not exactly visualizing but more something was moving in spinning motions and and with each spin I felt it wash over me, idk how to explain it very well, but then I suddenly came out of that state. I was still listening to mantras but I could feel a sort of tingling in my hands and legs. What does this mean? Should I be concerned in any manner about doing meditation like this without any guru or anyone guiding me?(I was just meditating because I wanted to feel one with Shiva) And is there anything to be mindful of while meditating? It felt like it opened up this new aspect of life for me and I want to learn more, it felt profound, idk how else to explain this