<human>: I was left about a year ago by my ex boyfriend. He said all the cliches, "it's not you, it's me". He told me that he wanted to break up after a year of being together because he feels like he wants to be single right now. He showed no warning signs of a break-up before his text (yes, he broke up with me via text). It obviously took me some time to get over him but now I don't feel anything towards him anymore, totally over him. 

Anyhow, I have been officially dating my new boyfriend for about 4 months now. I feel so happy in the relationship. However, I can't help but to feel scared that my new boyfriend will dump me, too, with no warning signs beforehand whatsoever. How can I deal with this? He's very affectionate and tells me I'm very important to him. I shouldn't be to worried about him breaking up with me. I still am and it makes me so stressed out.

Can you summarize the given text in a few sentences?
<bot>: last boyfriend broke up with me out of the blue because he wanted to be single again. Now scared that my new boyfriend will do the same.