After a time away, feeling drawn back but overwhelmed by guilt

For about a year and a half, I stepped away from the faith I was born into and once practiced devoutly. In that time, I fell into many wrongdoings, from major sins like associating partners with Allah and unlawful relationships, to dabbling in forbidden practices, causing hurt to others, and consuming what is haram. Recently, right after Eid, I went through a painful breakup. I was in a relationship with someone who wasn't consistent in their prayers and fasting, and they ended things, which left me heartbroken. It's been a little over a week, and today I felt something unusual-a strong pull in my heart towards Allah. I suddenly had this urge to pray, but I'm terrified to start because of all the sins I've committed, even the gravest ones. I feel completely lost and unsure what to do.