You should tell your husband, but bear one thing in mind: men very touchy about their sexual prowess, and even the slightest criticism, no matter how well-meaning it might be, is likely to be met with hostility. If you know how your husband usually reacts to something that annoys him, you can gauge for yourself what he will say and do when he feels that you are slighting his manhood.
There are ways of talking about this situation, without necessarily causing upset. Rather than being critical, try to steer the conversation around to the things he enjoys within sex, and then start describing the things that you really enjoy as well. Instead of telling him what you don't like, try telling him how wonderful it would be if he does this or that. This is a way of leading him to doing the things you want, and then by increase your own satisfaction tremendously. It would have benefits to him as well, as if you are content and enjoying your sex, you will be keen to have more, and if you do the things that excite him, you are both going to feel much happier with each other. Scientists call this positive feedback, and as opposed to negative feedback (criticising him and telling him how poorly he performs), this is a far more rewarding way of dealing with situations.
As long as his penis is of an adequate size, it really doesn't matter if it is not as big or thick as your previous lover. It just seems more important because you are not satisfied with the way things are. If your husband lands to give you the skills you want, and as long as his size is sufficient to do the job, you will enjoy it. It is a fact that a lot of women never achieve an orgasm penetrative sex, but a man who is a skilled lover understand that in many ways, his lips and tongue are far more useful in producing as breathtaking sensations that we love. If you teach him to perform oral sex on you, and teach him well, is penis size will be completely relevant. If you want something really big, by dildo, or spend a few hours in the vegetable market looking cucumbers!!! The reality is that no man can measure up, either in length or dimension to the last word thickness of an artificial penis, or a suitably sized vegetable as a substitute. There's nothing wrong with having these in the bedroom with you, when you and your husband are enjoying yourselves. He might even find it extremely exciting!!!
Communication is the key to a successful relationship. I'm not just talking about sex here, it works in every aspect of your relationship. If you can sit and discuss things calmly with each other, it will stop anything turning into bubbling resentment or outright conflict. A long and happy relationship starts with good communications. This means listening to each other as well as talking. Sometimes, when we are annoyed about something, you're so busy trying to argue our own point of view that we fail to understand how the other person feels. If you just count of five and relax, then let him say what he thinks, and vice versa, you'd be surprised at how much better your relationship can be.
If you preferred having sex with the other guy, you should have married him!!! But the fact is, you did it, so there's no point in longing for what you used to have, you don't, and you won't get it doing something drastic. You are married to this man now, and as the bow said, for better or worse. It is worse right now, then you need to make it better, and that starts with looking forward, rather than backwards. I'm not saying that you should forget your former lovers, That's just not realistic, but constantly holding up your husband against them and finding him wanting is never going to give you a solution to your current situation. Remember the past with fondness, but remember why you didn't finish up married to any of these guys. This
Other people have commented in this post, saying that you should love your husband as he loves you. If you had an arranged marriage, perhaps neither of you each other, and that is one reason why I am so opposed to arrange marriages. Two people who are thrust together by their respective parents may not even like each other much. Under such circumstances, it must be very difficult to make things work. But again, this is your situation, and you allowed it to happen. If you and he can talk to each other, and you try to be subtle as I suggested at the start of this post, there's no reason why you can't find ways of taking each other very happy in bed.
The very best of luck to both of you,