How to work on yourself, by yourself?

I’ve decided to get a gym membership, start to eat more healthy, take vitamins, etc. I tried this two years ago but couldn’t stick to it because I had no one to go to the gym with (my friends live a hour away and my boyfriend’s schedule didn’t allow him to have time for the gym). So it was hard for me to kick myself in the ass and force myself to go to the gym a lot especially when I was exhausted from my job. And as for eating healthy my boyfriend who I live with wasn’t interested in eating clean and would always bring home fast food or take us out to dinner.

How do you do it by yourself and motivate yourself?