It's normal for people to come back to your thoughts when you don't want them to. It still happens to me sometimes with people that I cut out of my life..... like half my life ago! Oh man that sounds sorta pathetic.

Yet I know it isn't actually pathetic. It's normal. Especially when it's a new decision and change... it's normal to question and doubt yourself, and to miss the person. But when you do, you need to remind yourself as to why the connection has been severed - remind yourself why it's healthier the way that it is. Acknowledge that you miss him, and why (you've said here that you feel it's just male attention that you're missing... totally normal and alright!) and then remind yourself why HIS attention isn't really worth wanting.

Then do something else. If you can't shake the thoughts... have a pretend conversation in your head. Turn it into a scenario where you tell them ALL the thoughts in your head that you likely never shared with them out of anxiety/politeness/whatever.

And you're spot-on about the fact that they are showing up consistently in your thoughts as you don't have other people around. But you aren't going to be replacing anybody. That makes it sound like you have only a limited amount of slots for friends, when you don't - it's limitless. You just haven't met the right people, yet. The more healthy interactions you have, combined with more time, will make the resurfacing thoughts less frequent and easier to handle.