Sometimes i regret being closed off most of my life

Even though im an introvert and not a really huge fan of meeting with people, i sometimes feel regretful over this and over the missed opportunities. Sometimes i feel regetful over rejecting an invitation i have done in the past which may have hurt the person inviting me who did it out of good gesture most of the times because that time will never come back with that person, i may have missed some good oppurtunity, maybe i would have more people who would care about me today if i would've built more connections. Idk but i sometimes feel this way even though i do tend to get energy drained after meeting with people and prefer to be alone most of the times.