I am responding to the OP and haven't read every post.
Four years is a really long time to decide something like this. If you are both very young, that might be reasonable (e.g. are still in college, the man can't support a family yet, etc.)
When I met my wife, she had determined she didn't want to have a boyfriend until she met the right guy. That was sort of my attitude, but I didn't want to overcommit too soon. When I was ready to propose, I wanted to propose then, not be forced to propose before I was ready, if you get what I mean. If I committed to her that she was the one I wanted to marry, just to date her, well, that was like proposing.
At one point, someone said something against our relationship, and she misinterpreted some things. She wrote me a note that maybe we shouldn't spend time together until I was sure. I talked her out of that. She didn't mean it that way, but that is almost like a 'marry me or else' ultimatum.
In her country, you can date for a long time, call each other friends' and then get engaged. But I felt like I was lying after a while when I kept calling her my 'friend.' She was my girlfriend. I took her out to dinner almost every night, took her to church, etc. She was able to be my girlfriend, I guess, and be at peace with that. I proposed about 5 or 6 months into our relationship, though and got married about 10 months into it. The Lord was in it. I prayed about the issue a lot and got peace about it, right after deciding to propose while in prayer.
This is just something to think about. Maybe he wants to propose, but like a lot of young men, is a little unsure about such a big decision. If he doesn't have the money to support you, that may be his concern, or he may want to wait until he is 100% sure (which in my case came after making the decision to accept what the Lord was directing me to and propose).
You have to be careful with decisions like this. On the one hand, if a man is never going to marry you, and you have kept yourselves pure especially as you have indicated you have, you don't want him to waste your time and it may be better just to suffer and 'cut your losses' in terms of time and emotional investment. On the other hand, you don't want to force a man to marry you by backing him in a corner. If you leave the door open for him to call you and talk to you as 'just friends', maybe take you out to dinner, etc. you can leave the door open for marriage proposals, etc. If you don't let him take you out unless he has a ring in a box ready for you, that is a lot of pressure to put on him, and it could be taken almost as an ultimatum.
Four years is a long time, though, depending on your age. If you had an honest conversation with you and he just doesn't see marriage as likely, you should move on. But if you are the one he would want if he would marry, but he is hesitant to actually do it, that is a different story. You'll also have to ask yourself how important decisiveness is to you in a husband.
