25 years and I hardly ever had sexual/romantic life

I don't know how to explain this, but here it goes.

I'm 25 and I hardly ever had any sexual or romantic experience. A combination of bad luck, bad decisions and bad behavior has bring me there.

My first kiss was when I was 18 in a local festivities. I had met her the previous year and she lived 500 km away, so we never managed to meet again, although I was in love for a while.

3 years later I met a girl on Instagram and start chatting. It was great and we were dating for a few weeks. I was about to lose virginity with her once but I couldn't get hard this time. Then one day she suddenly told me that she was just using me to make jealous one of my friends, but it hadn't work, so she didn't want yo bear me more.

That destroyed me completely for months, I saw myself as totally undesirable and still affects me sometimes.

Finally, six months ago, I met a pretty and funny girl in a party. But, a couple of days before our first date, she suddenly disappeared. As far as I've managed to guess (we have some common friends) she sufered a familiar death. I feel myself terribly selfish for thinking in my bad luck apart from hers, but I can't avoid it.

Apart from these experiences, I have some problems when trying to date a girl. My insecurities make me really hard to ask a girl I'm chatting for a date, because I find almost impossible that other person feels attracted to me.

Apart from that, I don't have any problem. I have a decent job and about to get a very good one. I have an incredible group of friends and I don't have problem to socialize with new people (dating thing doesn't count). My family is also great. I'm totally healthy and even in a very good shape. That makes me feel stupid for feeling bad just for my lack of romantic life, but I can't avoid it.

I just wanted to get some relief and maybe getting some nice advice, further the typical ones (be yourself, work your insecurities...)

TLDR: I'm a 25 year old virgin with very bad luck in love and some insecurities due to that.