First of, I'm very sorry to hear about your loss. That is a very difficult situation, and I'm glad you are ready to start dating again. Taking it slow is a good idea. It's probably for the best that you aren't meeting a ton of guys. You don't want to rush into anything that will cause you to get upset and close yourself off.

It could be that you're giving off a "don't approach me" vibe. That's natural, given that you're getting over a loss. The best way to get past this is to take things slow. Try to bring back the fun part of dating. Get to know a guy first as a friend. Pursue shared interests and have fun together. The more you get to know him, the more likely you are to get your guard down. Whether you realize it or not, you may be putting up deflector shields (Star Wars reference + 1!) in order to protect yourself from more heartache. The aftermath of a death of a loved one is an ongoing process. "Moving on" doesn't happen overnight. When you like someone, you may want to tell him that you are still getting over losing someone. If the guy is interested, he'll be willing to take it slow.

Getting out there is definitely a good thing. Accept offers from friends to hang out, go to parties, rekindle old flames. Being choose-y is a good thing overall, particularly now. When you meet a guy you like, have fun and give him a chance to get close to you. But taking it slow and being picky isn't a bad thing right now. If you're still feeling depressed, talk to a grief counselor, family member, or someone else close to you. For now, focus on meeting people and getting back into the swing of your daily life. The right guy will fit into that, and be willing to give you the time you need to heal.