Hello, and welcome to the forum
That's got to be tough, working in a call centre and trying to lose weight. You've got the stress of your work and the sedentary days to work with. I work in an office but I'm not chained to my desk...I get up for the photocopier sometimes, or to deliver things to other floors.
Is there any way you can just stand up every hour for a few minutes? Maybe walk in place? There are apps for your phone or computer that can remind you to get up and move at regular intervals.
Sorry to hear about your troubles with your boyfriend.
I ran into some rough times with my husband before I started on my current plan. However, the issue in my case was that I was unwilling to diet at the time, and he wanted to do it together. He's very supportive, but I just wasn't on board, and honestly I was terrified of losing weight, for fear of regaining it with interest like I have after previous attempts. When I formed a real plan and started calorie counting, he jumped on board and we've been helping each other keep on track since then.
So, perhaps if you outline a healthy plan to your boyfriend, he will be able to be supportive again, so you feel reassured?
I think it's important to note, it's not bad to eat "bad" foods sometimes. I eat plenty of "bad" foods, but I plan for them and eat reasonable amounts. It's completely okay to have a big huge calorific meal sometimes! Just not for every meal of every day.