How nice to hear from you again...and congratualtions on your engagement! No worries, your email does not show on the message.
To cope with rollercoaster emotions and energy, try doing a modified daily journaling where you specifically try to keep track of what triggers those times you want to hide. When you have an idea about what triggers the mood change, you'll know whether this is something that you can resolve by making some adjustments in your life, or if you need a therapist to help you sort through it.
While you're doing that, there are some effective self-help tools you can use to stay more in the present. Worry, depression, and anxiety are focused either on the past or future, which prevents us from being fully present in this moment.
One of the most effective therapy techniques can also be used outside of the therapy office, with success. DBT (Dialectical Behavioral Therapy) was developed for people with mood disorders, and involves tracking your moods, triggers, and learning how to stay in the here and now. An excellent workbook is available: DBT Workbook
For the times when anxiety is a problem, you might want to try EFT (Emotional Freedom Technique) It's based on the meridians of accupuncture, but works with finger tapping, not needles.
To learn the basic technique, watch this video: http://www.youtube.com/watch?v=UlCE4P6Ue0w
Then, you can find videos that will walk you through EFT on a myriad of different problems. My favorite instructor is Brad Yates http://www.youtube.com/results?search_query=eft+anxiety+brad+yates&oq=eft+anxiety&aq=1&aqi=g2g-m3&aql=&gs_sm=c&gs_upl=131496l135887l0l137961l11l9l0l0l0l0l523l2845l18.104.22.168.1.1l9l0
Here's another instructor with a specific script for anxiety. http://www.youtube.com/watch?v=zxk7cVPEOXw
And finally, there are some wonderful relaxation recordings that will help keep you in control of your emotions. Dan Siegal, PhD has some very good, free MP3 links on his website that talk you through the process. Here are the links:
You can download them, or listen from your computer.
Choose "Wheel of Awareness III http://drdansiegel.com/resources/wheel_of_awareness/ :
This combination of building self-awareness by tracking your mood and emotion changes, and learning coping and relaxing skills should help you feel like you're the one in control again, rather than emtions running the show.
I wish you all the best,