What I've learned about 'unconditional love' is that it's never perfect. There are always things that you don't love about someone. But if you look at a person as a whole, it's fairly easy to love them unconditionally. My unconditional love for one human being on earth isn't despite his shortcomings or faults. It's because they exist. I learned to simply stand up and shrug my shoulders and admit that there are very few things that would ever cause me to not love him... none of which I believe he is capable of. So regardless of how he annoys me or drives me crazy, my deeper feelings don't change. It took a long time for that to evolve. Part of being able to say that I love him without feeling stupid or guilty because of the things he's done in our relationships brought me that inner peace you're talking about. I try to be congruent.
Now, seeking it from someone else is another story. Get a dog.
True happiness I believe is never truly 100%. Otherwise, why would we try to pursue anything else in life? I think it's part of the human condition to seek it out. It's a motivator. Same goes for figuring out our trials, tribulations, etc. We seek out ways to understand them because we are rational beings. Mostly. However, sometimes the search itself becomes irrational and all consuming. Then comes your inner peace. If you can find a smidgen of inner peace, the trials and tribulations become less catastrophic. In regards to searching for hope after death, that's just not something I worry about. I really think you go where you believe you'll go. I'm not going to heaven or hell because I don't believe in them, personally, but who would I be to say that someone else isn't either, if that's their belief? Faith is powerful, no matter what it is in.
Crud. I need coffee. Did any of that make sense?