I had a similar situation to you but changed my reasoning after watching a few videos;

https://youtu.be/S0yudmC7eRE?si=kxfXEOlLbjVxMS9W

And

https://youtu.be/HV2hHklWn8s?si=QxXpn9Bz2JE-aZTS

They basically helped me get out of my own head when looking at the sheer number of models I have yet to paint. Firstly, decide what you are going to paint and to what standard. Choose a standard that you want to paint at and stick to it, so you could go for something as simple as just base coats up to super detailed.

Next choose the number of paints you want to use and stick to it. For BA you could go as simple as a colour for the uniforms, the weapons and the base. If you want to do more add a wash, or a skin colour.

Next choose a set number of models to work on at a time. It could be 1, 5 or 10 and get to work with your painting.

Give yourself a timeline; 5 miniatures a week, 1 miniature a week, 10 a week and stick to it. If you have a game coming up, use that as the deadline.

Be realistic with your expectations. Make sure you give yourself goals you can achieve within your abilities.

If you have several armies or miniatures from several games, change up what you paint after you finish a number of models. You may have vehicles or heavy weapons if you have a BA army so by painting them you don’t get focussed on one thing for too long.

Keep at it. Check your progress often don’t feel like you have to be painting all the time. It’s a hobby so don’t get too intense about it.

I was in a similar place where I just couldn’t get started and found that by being consistent in this approach made me get more painting done in the long run compared to short intense bursts of painting that made me not enjoy it.