Trust issues in my relationship between me (Male 30) and her (Female 26). 5 years into the relationship

I’m writing this because I feel lonely, insecure, and emotionally drained. My girlfriend and I broke up two months ago, and after reconciling, I admitted my past mistakes and have been working on this relationship day by day — giving her attention, making surprises, prioritizing her in my life, and consistently reassuring her, since in the past I was distant and didn’t value the relationship enough.

Since then, I’ve been honest and transparent with her, sharing my feelings and trying to include her in my decisions. But I’ve noticed that she hasn’t been putting in the same effort and has maintained a relationship with a male friend, with whom she broke my trust by not telling me when she hung out with him.

After our reconciliation, I had an open conversation about this male friend, expressing that I felt uncomfortable with her chatting with him. She always told me they were just friends and there was nothing to worry about. But two weeks ago, I decided to check her Instagram chat and discovered that she had sex with him three times during the breakup phase, which lasted one week.

I confronted her about this, and at first, she lied, saying she had sex with an ex-colleague from high school. When I showed her proof, she admitted it was with her male friend but remained silent afterward. After I insisted, she said she would stop talking to him, but at the same time kept mentioning how supportive and present he had been during crucial moments of her life.

It’s been one week since then. I’ve noticed some small changes — she’s been sharing Instagram reels with me, and I haven’t seen messages from him on her screen — but there’s no guarantee she deleted his number or blocked him, as I asked her to do.

She makes future plans with me like holidays and talk about marriage and having kids in which we have the same goal.

I really love her, which makes this even more hurtful. On top of that, I don’t have friends or much emotional support. I feel like I’m hitting rock bottom and don’t know how to get out of this. I just needed to vent and get your opinion. Do you think I’m being controlling or overthinking?