I’m very cautious like you and have become more cautious over time due to negative experiences with being used, deceived, betrayed, etc. I’m of the opinion that it’s better to be “overly” cautious than not cautious enough - especially with allowing people close. Nothing wrong with being super discriminating. Personally, I’m happier and calmer without extra people around and have really trimmed down my social circle/interactions. Life is hard enough without unnecessary human drama! Try not to doubt your instincts.