(With the disclaimer that I’m going to take a “Western” astrological perspective in my answer:) Depending on how “emotionally strong and stable” looks to you, I would agree with @Rosechalice, although Taurus is a sign that’s more interested in the physical manifestation than the “emotions.” If you wanted a sign that’s interested in emotions that’s strong (and “stable” in a similar way as Taurus), that’d be Scorpio, who’s all about emotions and is also a fixed sign.
A fixed water sign is an interesting dichotomy because water (emotions) is meant to flow. So, Scorpio becomes fixed by coming to its ways of dealing with emotions and then sticking to them, in a very strong and stable (but, not necessarily–erm–healthy?) way. “Stable” might not be the most helpful descriptor you’re wanting.
“Stoic,” to me, means considering factors other than emotions in terms of reacting to life and of decision-making. So, you might be wanting the practicality of Capricorn (and Taurus) and the goal-orientation of Virgo.
Believe it or not, Aquarius can be an incredibly “stable” sign (another “fixed” sign) and can be famous for its separation from the realm of human emotion. This could be another sort of “stoic.”
If you’re asking for your benefit, that you want to become more emotionally strong and stable, then look at your chart (or have an astrologer look at your chart) to see what’s making you be the emotional being you are today. Then use the fields to remedy those planets and their planetary aspects in your chart. That would be much more productive.
