I don't feel love for my parents, but I do feel love for HaShem.
As a child and a parent, I'm constantly working on understanding these relationships. Loving a parent is completely out of gratitude, loving a child is due to your ability to give to them. It's easier to love someone you give to than someone from whom you receive - it's a matter of emotional investment.
I've always felt abandoned by my parents (broken home, had to self-educate myself, etc.) and therefor find it hard to feel gratitude for anything they did provide. I'm constantly caring for my child so I find it very easy to love them.
Gd is a giver, we owe everything we have to Him. But that doesn't mean it's easy to love Him. It's hard to remember that every breath is from Him. If I make a profitable business deal, I find it easy to say "Thank Gd!". If I lose internet connection for three days and end up with a backup of angry clients, I don't find it as easy. The issue really is my lack of ability to realize that my "lack" of internet is a gain in some other way. Perhaps I was meant to spend more time with my family or work on things around the house during that time; perhaps it was very important that I had the extra help in guarding my eyes during that time. I don't know. But this is where the idea of "trust" comes in. Since it's very hard to see Gd's plan, we have to trust that everything is for the best and we're not just chess pieces in some fun game of His.
That being said, even if I was able to find a way to always feel gratitude to Gd, doesn't mean I'll end up loving Him. The key is finding a way to give back to Gd. If you can give, you can invest and if you can invest you can love. So, by using the following definition of love, "What's important to YOU is (now) important to ME", I'm able to learn to love Gd. I first have to see what's important to Gd, which usually involves checking what is written in the Torah. Once I realize what makes Gd happy, I can then speak to Him and say, "I'm doing this for you, so I can learn to love you."
After a long day I don't want to stay up late to speak with my wife, but I have an obligation. So I do it anyway and it in turn builds love. Eventually I want nothing more than to stay up and listen to my wife. I also don't want to get up early in the morning to speak to Gd, but I know it makes Him happy, so I do it, and sure enough it builds love.
My reply to you is simple: Love is finding out what is important to someone else and doing it, regardless of what it means to you. In this case, it would mean finding out what Gd wants and doing it for Him.
Because we're human, it's not so easy to only be a giver, we often need some level of taking. But in order to take without destroying love, there are a couple of things to keep in mind. First of all, you can receive, but don't take. Don't expect to be given anything, because if you do and it doesn't reach you, you'll experience the equation of Expectation + Reality = Disappointing. By training yourself not to expect anything from anyone, you'll also build an attitude of gratitude, which is item #2 of "things to keep in mind". By having gratitude, you'll experience a boost of energy than enables you to be more of a giver - until you one day reach the level where you can give unconditionally.
Give Gd what He needs, thank Gd for what He gives, through this you will find love. If you're not ready to try this on Gd, try it on a friend or spouse, experience human love and then go for spiritual love. You can also try it on yourself by giving your body what it really wants - sleep, healthy food, exercise, etc.
Thanks for posing the question, typing this out really has helped me think a ton. I hope it helps you too!
