Hi Amy,
It sounds like your anxiety (and possibly depression) are escalating lately. Sorry to hear you're going through this - good move coming here for some support.
Your sense of not feeling happy and often being on the verge of crying are very familiar and quite common when depression starts to creep in. You say that you have a lot to be thankful for, which is great, but be careful not to allow feelings of misplaced guilt to make things worse. Certainly, practising gratitude is an effective form of therapy but it never does us any good to compare or diminish our own suffering; Your pain is your pain, regardless of what you have in your life.
I feel it's almost a bit patronising to just say, "see a doctor". I mean, it's not as though you wouldn't have been able to come up with that idea on your own! But maybe, like me, there is something stopping you from looking for expert help. For me the barrier was a combination of a) being quite sceptical that anyone could really help me, and b) having a strange subconscious fear of inconveniencing people. I can say now that things only significantly started to improve for me after I spoke to my GP (a good one - don't be afraid to try a few) and put together a plan. I really recommend you at least start a conversation with your doctor around what you're going through.
If you're feeling alone because of a lack of understanding amongst your family and friends, you will find some good advice around these forums and on this website about how to communicate what you're going through, and how to give your loved ones the information they need to support you.
You always have support here, regardless. I hope things improve soon, take care and good luck.
