Signals are tricky things. It's hard to judge the way guys think because they are so different from us. The best way to know for sure is to straight out ask, but I understand us girls don't like to take the reins that way. I doubt anything is born out of pity. People wouldn't send you gifts or spend time with you if they just felt sorry for you. There's a limit to charity, my dear.
First loves are hard. You will never forget them, and it's hard to move on at times. If you feel like you're ready, then it's time. There's no 'long enough' where love is concerned. You will know when you're ready, and holding on too long can be unhealthy too. So long as you're sure about what and who you want, you will know when the time is right to try again.