I think take up lessons again this way or only commitment would be turning up every day! Next thing I would do is if you find that you like it, love it even then I would take out a horse on lease , this way your commiting but it is not as big of a commitment as buying your own horse!mayby even offer help at your local barn grooming, tacking up and caring for the horses their on a regular basis!
If you still don't have any intrest then I would advise you to just give it up and go back to having lessons!
And why don't you if your wanting a dog so much just go to your nerest shelter and adopt one! See how it goes but all I would say is don't go rushing in to something your not 1000000000% commmited to! I love horses and wake up everymorning thinking about them and go to sleep everynight thinking about them too! I can't imagine my life without them in it some way or another! There is'nt 1 minute were I don't have them in my mind! Im not saying that this should be the same for you Im just saying that if you think about them one day and then the other the nothing , that tells me that your not sure weather or not you really do want them in your life?
But one things for sure: do not buy one until your a million percent sure your ready and willing!