Hello and you are a good person and very worthy. The world is a better place because you live within it. Believe in you, love yourself and do not depend on others to validate your worth.
The new guy..........drop kick him to the curb and the next time you see him hold your head up high and walk right on by.
Most of us remember our first love and when you are much older you still remember that one person and wonder how they are. It is normal. That does not mean you should necessarily get back with him.
I would advice you to just be in the moment and when you meet someone recognize a con line when you hear it. A solid relationship takes more then one sudden meeting to be the real thing. Only in movies do people look accross the room and there stands the love of their lives.
Take care and keep posting.