There's a Buddhist principle which says we are two beasts (the dog being the animal I believe is applied in this analogy), one negative and one positive, one feared and one loved. Whichever dog we feed is the strongest of the two. This can of course change at any time, and we can indeed ‘snap out' of a negative state if a situation demands us to be confident in dealing with it, and we then allow ourselves the merit of being able to command the right energy. A knock at the door from an unexpected guest can do this, or a win on the lottery. Aside from rare possibilities such as these, the best place to find this positive energy is in something around you at the time, something that might seem so commonplace as to be unimportant. But cleaning the kitchen or writing a blog or doing anything constructive with our time feeds us love energy, for we see a positive result, we've done something, and we are allowed to love what we do - that's the whole point of the exercise. Beating ourselves up for things we've said and agonising over mistakes we've made or might make is tantamount to pouring weedkiller over a growing lawn.
Synchronicity is, if my interpretation is correct, a point in time when spiritual and physical boundaries meet, when an influence beyond our sight calls in a card to be placed on our table, when the Universe (or perhaps safer to say, its representative at the time) responds to something we need in a way we can perceive. For this reason, synchronicities are allowed to be personal, the moments in which they occur reflective of things that are meaningful only to us, and if we are lucky enough to share a synchronicity with another person or people to whom the meaning is also clear, the corresponding energy pulse is that much greater. We recognise this at a level we don't fully understand, but undeniably share, and this is why Jung and Planck and so many other great philosophical and scientific minds have puzzled over its existence, power and complexity. The fact that it may be comparatively simple in the essence of its application does nothing to quell the sense of mystery synchronicity inflicts upon our waking senses.