Thanks for sharing your "Engagement Story" and your views on the purpose of engagement, I enjoyed reading this post very much.
MrS and I went through what sounds like similar stages, although we framed them differently:
We started out as casual-then-closer friends who had sex while seeing other people. (Immediate family knew we were "friends", extended family not in the loop)
After six months of deepening friendship and developing feelings, we had a "big talk" and determined that we were, in fact, a "couple" (i.e. BF/GF) and we talked about expectations and boundaries. (Immediate family knew we were "dating", extended family knew we were friends)
After six months of "couplehood" we made the transition to "cohabitating couplehood." (we also had roommates) (Immediate family knew we were cohabitating, extended family knew we were "dating")
After two years of "cohabitating" I was moving across the state to pursue further schooling - MrS elected to come with me. This, to me, marked another level of commitment - the "making life decisions on the basis of furthering the relationship" level. We discussed engagement at this point, but I asked to defer this at least another year - to see what living together alone, away from friends/family and pursuing a rigorous course of study would mean to our relationship. (Immediate family knew that engagement was on the table, extended family knew we were "cohabitating" - i.e. he gets invited to Thanksgiving dinner at Grandma's house as "guest").
After 1.5 years of "pre-engagement cohabitation" he proposes, I accept, we set a date, we announce our engagement to all. (Immediate family says "Finally!", extended family transitions from "guest" to "future relative")
6 mos later we are married. (...and a good time was had by all
) - That was 16 years ago.
OP - I agree with the others, I don't know that I would make too much of your rush of emotion after a great weekend while you are still in NRE phase. No need to be making any sweeping statements or rash decisions. Keep doing what you are doing - exploring your relationships and enjoying the love you are experiencing in the here-and-now.
You should talk to your fiance about what engagement means to each of you and how you both see your future together unfolding - keeping in mind that as each of you and your relationships grow and change, you might be in a very different place in a few years.
Your early 20's is still a time of flux and change - you explore yourself and start figuring out who you are and what you want out of life. You start to make choices that shape your future - but these choices should be flexible, to allow for continued growth.
PS. MrS was MY "first proper relationship" as well - we met when I was 18 and married at 22. Dude is technically my "second proper relationship" - this time around I seem to be moving through my "stages" a little faster