What should I do about my creepy seminar teacher?

I (21 F) thought I had a good relationship with my seminar teacher at first. I guess he's around 50 years of age and is rather quirky.

After class he started inviting some of us out to the pub. After the second time we had all been to the pub together I got an email from him following up on our earlier conversation (he shared a few links to things we had spoken about earlier on). I replied to say thanks but it carried on from there with him continuing to email me & it turned into a back and forth conversation.

We spoke a lot and it resulted in him becoming quite attached to me (sending me paragraph after paragraph every night about his life). I think I felt sorry him because he lived at home with his parents, was single, didn't seem to have a great social life outside of work and was generally a little bit odd so I continued chatting to him on email or the uni chat and he would sometimes invite me out for coffee. I felt awkward saying no so I met up with him a few times thinking we would be disgussing my work but he spend the whole time speaking to me socially. If I didn't reply to him within a day or declined a coffee (usually because I was busy studying or going out with flatmates) he would behave standoffish with me in seminars so I would feel super guilty and would email him apologising for not replying quickly enough. Or sometimes he'd send 100 plus messages in a row at strange times of the night.

He told me he had saved every email and chat exchange we had and remembered details down to the date he first taught me, college results and he had looked up my address on the computer system. I backed off because I was finding it intense.

He sent a super long email to my personal email address about how much he missed our friendship and that he was sad I didn't want to spend time with him anymore. I ignored it, blocked him and reported him to my personal tutor but I don't think anything has been done.

Luckily I completed the module so I'm not taught by him anymore and he has left me alone. However I've met two other students on my course (both female) who have been taught by him and have experienced THE EXACT same stuff with him sending them messages outside of Uni and trying to be befriend them but I don't think they have reported him.

I realised that he was only ever interested in the pub trips when it was just the girls. He was always busy if the boys were coming along too.

I don't know what I can do because he hasn't actually DONE anything and he could just be lonely but he does only seem to be interested in meeting up with his female students who are less than half his age??? Am i over reacting or should something be done?