Realtor, it seems to me that your expectations are out of whack. After all, even a "superstar SR" will never close every prospect (and probably wouldn't imagine it could happen for them).
To put my commentary into perspective:
1. I've been in B2B sales and sales management for 30 + yrs:
2. My wife has been extremely successful in selling real estate for shy of 20 yrs.
Your observation is telling: "Stepping back and looking at this objectively should I view this as
(a.) I missed out on a sales because I lacked the skill to get them to buy one of the homes I showed them
(b.) I did everything I could to increase the chances of them buying"
Firstly, you shouldn't assume that there is a skill, "to get them to buy one of the homes I showed them". Rather, you need to focus on identifying the client's wish-list (ie. what are the absolute, drop-dead features which will motivate you to buy?), their timing, their financial situation, etc. Without this in-hand (agreed upon by the parties), clearly, you weren't in a position to ask for their business.
Secondly, it should be pointed out that you probably didn't "miss out on a sale" because without some real effort spent qualifying, you're probably dealing with tire-kickers (suspects).
It appears evident that you need to adjust your expectations, so, that more time is spent developping the front-end.
Good luck & Good selling!
Pat