Everybody contributes their own perspective on deep and broad things such as what living with Simcha means, and whether our root problem is the lack of Simcha or whether it is really something else.
I'm also here to share my chelek for the benefit of whoever wants it. What I have discovered is the following:
Yes, living with Simcha is what Hashem wants, and what we want. Yes, living with Simcha does not necessarily mean dancing and feeling great while r"l dying, losing a loved one, or losing our sobriety. Rav Twersky pointed out to me (in his nice book "Let Us Make Man") that to him, accepting suffering b'simcha simply means accepting it rather than running from it. That will only happen if we accept that it must be for the best, that it has a purpose. It's a totally different experience than just knowing that everything is for the best and is for a purpose. (Knowing without accepting is not enough). Being a huge talmid chochom may have no impact on my acceptance, at all.For example, the calm we felt as children witnessing our mothers or fathers (especially when we misbehaved), will often speak louder to us in this than the Torah ever will. We internalized that it's "ok" even when things didn't go their way. And conversely, if they freaked out when things did not go their way (and "things" may include: me, other people, their business, life, or health, etc.), I may have learned that "it's just horrible when things do not go my way!" So all the "information" about Hashem, Torah, and emunah, will likely be irrelevant if my heart feels that the way things are really "supposed" to work is my way.
If you agree at all so far, you may be wondering what hope there is. In other words, "how do we change our hearts"?
Put simply, working the 12 Steps in a chevra of real people actually changed my heart. I came to feel differently about G-d, about myself, and about other people through working the steps with my sponsor (another addict).
But I cannot give all the credit to that, for the other two factors were: Hashem, of course, and surprisingly, my Lust (l'havdil)!
B"H, my Lust drove me to see and do things differently - cuz I had to get away from it, and still do. I took some direction, worked the steps, and apparently Hashem made (and still makes) the actual changes within me happen, in order to stay sober. Not to be a better oveid Hashem, mind you, but for me to stay sober. "Al kein yoreh (from a loshon of "forcefully throwing" - as in "oh yaroh yi'yareh" by har Sinai) chatoim (that's me)ba'derech." In the end, am I doing Hashem's Will any better? It sure seems that way to me.
And so it may be as far as "living with simcha" is concerned: Working or focusing directly on "living with Simcha" may be a giant waste of time for many of us. It was for me. Just like working directly on living without the tyranny of Lust. A total waste of time... look at my track record.
On the other hand, when my actual attitude toward Hashem, toward myself, and toward other people truly changed a bit (through working - not reading - the steps, in my case), I finally got some of the Simcha, and finally got some of the freedom from Lust.
So, maybe our entire problem is our lack of Simcha! But to me, the nature of the problem is not always relevant. As Rav Twerski says: knowing I have a broken leg will not heal the leg. It's only what I need to do about it that matters. So, some here may be more inclined to respond by fixing it ourselves, i.e: "being more besimcha". I choose to respond by not concerning myself with simcha (or with "beating" lust), at all!Instead, I learn to accept the truth about myself, Hashem, and other people. As a result, everything in my life is getting better - on His timetable.