
OP you're still really young and i don't blame you for feeling different about your bf. life changes so much from 16 to 20 years old. maybe the values and feelings you had at the start of your relationship are different now. what made u "icked" from your bf? were you just attracted to your crush's looks or did they treat you in a way your bf doesnt but you wish he would? hopefully you guys can talk about this stuff together. but its okay to admit that its time for something else.
You know this spark stuff is a paradox. Nature will produce a better person overtime and one can eventually run into this person. It really does depend on the context but fun and games can’t be sustain for long and no tv show can entertain people forever. Thus it is the question about the purpose of life and also why be with someone. Virtue and virtue alone should be the sole motivator because pleasure betrays.