I am going through the same thing right now. My relationship wasn't quite as long as yours, only just over a year long, but I have never felt for anyone else how I felt for him. Still, this is not my first time on this merry-go-round, which also definitely helps. I also know the clichés don't help a single bit at all, and can even make you feel worse instead. Here is practical advice and also how I do it:
First, what helps the most for me is to schedule time for myself to grieve. I write a journal daily, for an hour and a half usually. I don't actively think about what to write but just write whatever comes to mind, often it is good memories from amazing times we shared together that pop into my mind. I have found that writing them down and crying about them helps me release them, so they stop popping up randomly after that. Sometimes I feel angry, or disappointed or other feelings either toward myself or him, and those go in there as well.
Journaling helps me put the thoughts out of my mind when I don't need them, like when I go to the grocery store and am bombarded with memories from ridiculous things that remind me of him. I know I will deal with them later when I journal, and it helps my mind calm down about them. It gives me a tiny, but much needed sense of control in a situation where I otherwise feel entirely lost. After I am done I always feel much better, and I have a much better perspective on the situation.
I also meditate daily, for at least 15 minutes. I also find working out helps, even if it feels like the very last thing I want to do. If you have a hobby you have always wanted to try, do that, it will help you take your mind off things for a while. If you don't have one in mind and don't know how to draw for example, try learning how to that. Anyone can actually become good at drawing, it just takes practice. The feeling of progress will help you progress through the break-up, and feeling like you are accomplishing things on your own helps a ton.
Eat healthy! This is even more important now than usual. I have totally lost my appetite, and eating right now makes me nauseous, but I do it slowly anyway. This is very important! Junk foods like ice-cream and chocolate make you feel good for the moment, but you will have to pay it back in a short while by adding guilt or feelings of further loss of control to the mix of chaos in your heart and mind.
Do something for someone else every day. Helping someone else in need will make you feel better about yourself, and take the worries off your mind for a bit. It also helps you feel less lonely in your struggles. I guess today you are it for me, so thanks for helping me by letting me help you!

Feel free to send me a message if you feel like talking.
Now I am off to my journal and tears!