The only thing about speaking out on things you hope to happen in the future is that your roommates might begin to think your slightly crazy. They walk to the bathroom and come back and low and behold their roommate is yet again repeating "I am strong and healthy and happy". I have found that even though I am pretty young still, it's easy for me to see how uncomfortable people get when you ask them questions that require some introspection. They don't want to think about their emotional state because the majority of the time it dusts off the box that they hid deep inside themselves for several years, maybe even decades. They often will stray away from situations and people that bring them outside their little corner of a comfort zone and that's where they wish to reside, forever.
Speaking out to the universe is something that I do not mind being called crazy for. Your mind has so much power over you as a human being if you give in, take it from somebody with anxiety. The thing is, it doesn't have to be anything about your emotional state, you don't have to just speak out upon feeling better, you can speak out on anything that you feel is a roadblock in your path to success. "I am strong and capable and generous, I am hardworking and deserving of all good things that come my way". Literally just verbalizing how you want your day to go, how you want to treat people or how you want to deal with a situation, starting these sentences with "I am" gets the hardest part out of the way.
Now that you've spoken about how you are currently doing/feeling/acting your mind has no choice but to follow through.
You've done the hardest thing already, you have gotten to that place by saying it. For instance, when you're unreasonably flustered over a minor situation and you feel your gut giving way to emotions and doubt, the last thing you feel is strong. Taking a second to step back and remind yourself that you are a kick-ass human being and that in fact 'you are strong and, well, kick-ass' you have no choice but to follow through.
Growing up I had no idea what to do when I began to feel panicky, something that tags along with being an anxious person. I would immediately hand over my calmness and sanity to fear and let it break me down with little to no setbacks. It was the first way my mom and people around me that I have met in my life taught me how to let things wash past you. They'd tell me to take a step back and remind myself that I am so safe and capable to overcome any obstacle that is placed before me. Eventually, as I got older I was able to get past any intruding thoughts by just bringing myself back to reality, back to the realization that in fact, I am capable of conquering all things before me. Just like you, and just like every person that exists today.