I've just begun seeing a man who was married to a friend of mine who unfortunately died 2 years ago. They married young and he is now only mid twenties. We were never close and never knew him before just recently crossed paths. This is tricky in itself!
But it seems like he's trying to rush everything and after couple weeks, has already brought up marriage and kids which is when I decided to back off but confronted him about it and he explained he only wanted to know if that's something I was thinking of in the future because he wants a serious relationship not a casual one and that he wasn't suggesting that he wants it straight away but wants it before he's 30 as he feels time is running out. I've tried to explain he is still young and he shouldn't feel that way and I want to be there for him.
He has said that he has always let his heart get involved easily and quickly which is why he has already come close to saying 'i love you'. I really like him but it's all feeling too much too soon. He suffers from depression and self esteem issues which he has said he is working on but that also means he's very clingy and needy and needs constant reassurance, something he has been open about but if I'm not giving him that it seems to upset him and it feels stressful trying to not say the wrong thing all the time.. I'm just basically wanting to know if this is normal and something he can work through or if he's just using me as someone to help him get into that situation again. All the discussions we've been having have been over text which I don't really like. Its absolutely fine in person and I enjoy spending time with him but I just want to know how I could raise these issues with him and if it's even right to? I don't want to hurt him because I'm not sure of the effect it will have on him.

Perhaps this guy is trying to fill the gap your friend left, they say friends are similar and maybe he sees her in you.
I think friends is the best option until he has his personal issues sorted.

I would keep holding him off from rushing too much too. Right now you can't be sure if he is the clingy, needy type or if it is a result of his being lost over the loss of his wife.

He is trying to fill the gap.I have learned that this "too much too soon" is always in re-bound relationships.

The good news? You can date him without fear of him going back to his ex
(I mean that... without being rude... though it comes off as... anyways)

But be aware that all the extra energy invested in you,is meant for her,he's basically subconciously pretending you're her,and continue-ing where they left off.

It seems right now he just needs a friend.

There are a lot of red flags here, and dating may be fine for now, but never be afraid of expressing yourself honestly to him as your concerns are very real.

Talaniman Rule- Don't be rushed into anything until you have the facts to make a good decision for yourself

Too much too soon is never any good - listen to what your intuition is telling you.

I'd be honest with him about how you feel - how's he going to learn otherwise, and temper his behavior? Keep it friendly and let him know that you're not ready for a serious relationship yet.

Let him also know that not all relationships have to be serious or have certainty of love, marriage, kids, etc.

It's possible to have fun and enjoy someone's company without the certainty that anything will eventuate.

Life's not predictable, I would have thought he's have an understanding of that!