Goggley, you sound like you have so much anxiety noe you are ready to burst! Instead of trying to force your brain to stop churning, try letting it go for a while, take a couple of minutes and just let the thoughts come, but let them go. They might stir an emotional response from you, but they generally will change shape and dispersee like clouds if you make a point of not catching onto them and pinning emotions on you. While you are doing this, don't set a value on the thoughts like, "Good" thought or "bad " thought. Juust let them come and wander right back out.
I am much like you. I have a tendeny to get very strong opinions that don't let themselves be nuanced much. I find that this technique helps me ALOT, but it needs to be practiced, and I am far from using it in all parts of my life. It is murder when my either-or thinkiing and anxiety totally paralyses me. I hope this can help you some, and good luck with the test. As far as love; yes, absolutely, you are worth someone picking you first and devoting a life to you if you do the same. I really think so.