My suggestion is to stop following your ex on IG and anywhere else. Since he is a liar, he is not to be trusted. I wouldn't text him either or contact him again in any way. Go no contact. Though it's hard to do, and I know how tempting it is to still text or check up on your ex, it's truly for the best, for your mental health and happiness. This too shall pass, as trite as that sounds, it's sooo true. Go no contact and the greater emotional distance you get from this man, the better you will feel.